₦airaland Forum

Some birds are at the top of a roof and some at the bottom. If you bring one bird from the top and add to birds at the bottom they become equall. But if you take one bird from the bottom and add to the birds at the top, the birds at the top double the birds at the bottom.

How many birds are at the top and bottom of the roof?

Before disruption there were 7 birds at the top and 5 birds at the bottom
Explanation/Analysis: Let the letter 'B' denote a bird
INITIALLY

TOP ~ B B B B B B B
BOTTOM ~ B B B B B

CASE 1
TOP ~ B B B B B B (When one bird has been
taken from the Top to the Bottom)
BOTTOM ~ B B B B B B (The addition made the
number of birds to be same)
CASE 2
TOP ~ B B B B B B B B( One bird has been
added to the Top from the Bottom)
BOTTOM ~ B B B B ( The loss of one bird here
made the new population at the
Bottom to be half that at the Top)

#MATHEMATICALLY
TOP BOTTOM
Originally 7 Birds + 5 Birds =12 Birds

Case 1 : 6 Birds + 6 Birds = 12 Birds

Case 2 : 4 Birds + 8 Birds = 12 Birds

There are seven birds at the top and Five birds at bottom. If u remove 1 from the seven birds at d top nd add to the ones at the bottom they becomes 6 birds each. But if u take one from the bottom nd add to the one at the top, the one at the top becomes 8 while the one at the bottom becomes 4. Then that at the top doubles that at d bottom.
Top =7
bottom=5

ebbybest:
There are seven birds at the top and Five birds at bottom. If u remove 1 from the seven birds at d top nd add to the ones at the bottom they becomes 6 birds each. But if u take one from the bottom nd add to the one at the top, the one at the top becomes 8 while the one at the bottom becomes 4. Then that at the top doubles that at d bottom.
Top =7
bottom=5

You are correct ooooo I failed it sha

ebbybest:
There are seven birds at the top and Five birds at bottom. If u remove 1 from the seven birds at d top nd add to the ones at the bottom they becomes 6 birds each. But if u take one from the bottom nd add to the one at the top, the one at the top becomes 8 while the one at the bottom becomes 4. Then that at the top doubles that at d bottom.
Top =7
bottom=5

You are correct ooooo. I failed it sha

kstadaura:
Some birds are at the top of a roof and some at the bottom. If you bring one bird from the top and add to birds at the bottom they become equall. But if you take one bird from the bottom and add to the birds at the top, the birds at the top double the birds at the bottom.

How many birds are at the top and bottom of the roof?

Let the number of brids at the top be X
Let the number at the bottom be P

Take one from the top,add to the bottom and they become equal....... X-1=P+1....equation i

Take one from the bottom,add to the top and the top doubles the one at the bottom X+1 = 2(P-1) ....equ ii

From equation i.... X-P=2
From equation ii.... X=2P-3

Since X = 2p-3 from equation ii.. We substitute in equation i..

Therefore... 2P-3-P=2
2P-P=2+3
P=5

Since P = 5... We substitute again...
X-P=2
X-5=2... X=7..

Therefore... (Top)X= 7 and (Bottom)P=5 ..

x-1=y+1....(1)
bt i can say dat x+1=y+3, dat is bcus d interval btwen x nd y is 2. 2(y-1)=x+1...(2) bt x+1=y+3. so put dat in eqn 2. so 2y-2=y+3. therefore y=5. put y=5 into eqn 2. 2(4)=x+1 therefore x=7. so birds at d top is 7 while at d bottom is 5

ebbybest:
There are seven birds at the top and Five birds at bottom. If u remove 1 from the seven birds at d top nd add to the ones at the bottom they becomes 6 birds each. But if u take one from the bottom nd add to the one at the top, the one at the top becomes 8 while the one at the bottom becomes 4. Then that at the top doubles that at d bottom.
Top =7
bottom=5

you are the first person that got it right,with simple explanation.

Ksslib:
Let the number of brids at the top be X
Let the number at the bottom be P

Take one from the top,add to the bottom and they become equal....... X-1=P+1....equation i

Take one from the bottom,add to the top and the top doubles the one at the bottom X+1 = 2(P-1) ....equ ii

From equation i.... X-P=2
From equation ii.... X=2P-3

Since X = 2p-3 from equation ii.. We substitute in equation i..

Therefore... 2P-3-P=2
2P-P=2+3
P=5

Since P = 5... We substitute again...
X-P=2
X-5=2... X=7..

Therefore... (Top)X= 7 and (Bottom)P=5 ..

Bro i salute.

kstadaura:
you are the first person that got it right,with simple explanation.

Thanks, but at a point it was very confusing.

kstadaura:
Bro i salute.

I salute too.

If you have more,pls dont hesitate to post to keep minds busy.

Ksslib:
I salute too.

If you have more,pls dont hesitate to post to keep minds busy.

Here is another one for you and everyone:
A certain number of horses and an equal number of men are going to somewhere.Half of the owners are on their horses's back while the remaining ones are walking along leading their horses. If the number of legs walking on the ground is 70, how many horses are there?

ebbybest:
Thanks, but at a point it was very confusing.

Another question posted. Give it a try.

kstadaura:
Here is another one for you and everyone:
A certain number of horses and an equal number of men are going to somewhere.Half of the owners are on their horses's back while the remaining ones are walking along leading their horses. If the number of legs walking on the ground is 70, how many horses are there?

Let the number of Men be X
And the number of horses be P

Number of horses equal men,so we have X=P...(eq i)

Half horses are occupied and half are not.And we know that occupied horses plus not occupied horses gives us the total horses.. So P/2 + P/2 = P...(equation ii)

Number of legs walking on the ground is 70. And since one man has two legs,it means they are 35men walking..

Since equation i said X=P...all we gats do is look for total number of men which MUST be same as total horses. No be me talk am,na the equation talk so.

Total number of men=those walking +those on horses..
I..e.. X= 35+ X/2 ... do l..c..m and multiply.. we have... 2x=x + 70.. x=70..

Total number of men(X)=70
So total horses(P) must be 70.. According to (equation i)... X=P

Sorry for the long method. Just wanted to avoid confusion..

Am I correct?

kstadaura:
Here is another one for you and everyone:
A certain number of horses and an equal number of men are going to somewhere.Half of the owners are on their horses's back while the remaining ones are walking along leading their horses. If the number of legs walking on the ground is 70, how many horses are there?

There are 10 horses and 25 men
now if 10 men are on the 10 horses 15 men will b walking on foot.
A horse have four legs and a man has 2legs.
4*10(number of horse legs)=40
15*2(number of man legs)=30
40+30=70
70 legs is the total number of legs walking on the ground.

cc.. Teempakguy .

You might like this.

Ksslib:
Let the number of brids at the top be X
Let the number at the bottom be P

Take one from the top,add to the bottom and they become equal....... X-1=P+1....equation i

Take one from the bottom,add to the top and the top doubles the one at the bottom X+1 = 2(P-1) ....equ ii

From equation i.... X-P=2
From equation ii.... X=2P-3

Since X = 2p-3 from equation ii.. We substitute in equation i..

Therefore... 2P-3-P=2
2P-P=2+3
P=5

Since P = 5... We substitute again...
X-P=2
X-5=2... X=7..

Therefore... (Top)X= 7 and (Bottom)P=5 ..

nice work.
Help me tell the op that it is an algebraic problem. Not arithmetic.

Kstadaura, any other one?

llaykorn:
Kstadaura, any other one?

Try this:
A woman is engaged to work for 16 days.She is paid 2nr each day she works and fined 0.40 each day she stays away.At the end she received 24.80 in all. For how many days does she stay stay away.?

Teempakguy:
nice work.
Help me tell the op that it is an algebraic problem. Not arithmetic.

Noted and thank you. Its only a kid and arrongant person that will not accept correction, hope we will not have their likes in this thread.

New problem posted.Give it a try.

Ksslib:
Let the number of Men be X
And the number of horses be P

Number of horses equal men,so we have X=P...(eq i)

Half horses are occupied and half are not.And we know that occupied horses plus not occupied horses gives us the total horses.. So P/2 + P/2 = P...(equation ii)

Number of legs walking on the ground is 70. And since one man has two legs,it means they are 35men walking..

Since equation i said X=P...all we gats do is look for total number of men which MUST be same as total horses. No be me talk am,na the equation talk so.

Total number of men=those walking +those on horses..
I..e.. X= 35+ X/2 ... do l..c..m and multiply.. we have... 2x=x + 70.. x=70..

Total number of men(X)=70
So total horses(P) must be 70.. According to (equation i)... X=P

Sorry for the long method. Just wanted to avoid confusion..

Am I correct?

Yes. Thats really commendable. i like the way you break the answer.

New problem posted.

ebbybest:
There are 10 horses and 25 men
now if 10 men are on the 10 horses 15 men will b walking on foot.
A horse have four legs and a man has 2legs.
4*10(number of horse legs)=40
15*2(number of man legs)=30
40+30=70
70 legs is the total number of legs walking on the ground.

Brilliant. You know what i like about your answers? they are straight to the point.

Another problem posted.

kstadaura:
Try this:
A woman is engaged to work for 16 days.She is paid 2nr each day she works and fined 40k each day she stays away.At the end she received 24.80 in all. For how many days does she stay stay away.?

2naira *16days =32
32naira -24.80=7.2
2naira * 12= 24 NAIRA
16 days -12 days= 4 days
The woman stayed away from work for 4 days.

ebbybest:
2naira *16days =32
32naira -24.80=7.2
2naira * 12= 24 NAIRA
16 days -12 days= 4 days
The woman stayed away from work for 4 days.

i will give you 85/100. you really try but the final answer is not correct.

Teempakguy:
nice work.
Help me tell the op that it is an algebraic problem. Not arithmetic.

Yea,.. all join.. He has accepted the correction though.

kstadaura:
Try this:
A woman is engaged to work for 16 days.She is paid 2nr each day she works and fined 40k each day she stays away.At the end she received 24.80 in all. For how many days does she stay stay away.?

Since the woman didn't receive 32naira at the end,it means she skipped worked for ATLEAST a day..

Now,assuming she skipped for just a day,her cash at the end will amount to 30naira. Also remember that she was fined for 40k. So how she still took about 24.80 home at the end still baffles me.

This is 40,000naira we are talking about here. I think the question is flawed.

And with respect to the horse problem you gave before this,one of either myself or ebbybest has to be wrong. We cannot both be correct.

Ksslib:
Since the woman didn't receive 32naira at the end,it means she skipped worked for ATLEAST a day..

Now,assuming she skipped for just a day,her cash at the end will amount to 30naira. Also remember that she was fined for 40k. So how she still took about 24.80 home at the end still baffles me.

This is 40,000naira we are talking about here. I think the question is flawed.

And with respect to the horse problem you gave before this,one of either myself or ebbybest has to be wrong. We cannot both be correct.

Sorry pls its 40kobo not thousands.

Sorry i'm late, guys. My battery died after my last reply yesterday.
Well, it seems no one has solved that last question yet. So, let me get to that.

Let the days she worked be x.

Let the days she didn't work be y.

We know that she was required to work for a total of 16 days. Hence,

x + y = 16 . . . . 1

Also, she gets paid 2 naira for days she worked and 0.4 kobo was deducted on the days she did not work. Giving a total of 24.80

Hence,

2x - 0.4y = 24.80 . . . . . 2

we are required to find the days she stayed away. Hence, we need to find y.
A very easy way would be to use determinants. But I thought they may be too technical. So, we will use substitution.

So,
x = 16 - y . . . . .3

Sub. 3 into 2.

2(16 - y) - 0.4y = 24.80

=> 32 - 2y - 0.4y = 24.80
=> 32 - 24.80 = 2y + 0.4y
=> 7.2 = 2.4y
=> y = 7.2/2.4
=> y = 3.

So, she stayed away for three days.

kstadaura:
Noted and thank you. Its only a kid and arrongant person that will not accept correction, hope we will not have their likes in this thread.

New problem posted.Give it a try.

no problem.
I've done that.

Teempakguy:
Sorry i'm late, guys. My battery died after my last reply yesterday.
Well, it seems no one has solved that last question yet. So, let me get to that.

Let the days she worked be x.

Let the days she didn't work be y.

We know that she was required to work for a total of 16 days. Hence,

x + y = 16 . . . . 1

Also, she gets paid 2 naira for days she worked and 0.4 kobo was deducted on the days she did not work. Giving a total of 24.80

Hence,

2x - 0.4y = 24.80 . . . . . 2

we are required to find the days she stayed away. Hence, we need to find y.
A very easy way would be to use determinants. But I thought they may be too technical. So, we will use substitution.

So,
x = 16 - y . . . . .3

Sub. 3 into 2.

2(16 - y) - 0.4y = 24.80

=> 32 - 2y - 0.4y = 24.80
=> 32 - 24.80 = 2y + 0.4y
=> 7.2 = 2.4y
=> y = 7.2/2.4
=> y = 3.

So, she stayed away for three days.

Excellent, am impressed by your answer.

Another q will be available in the evening.

A bird shooter was asked how many birds he had in the bag. He replied that there were all sparrows but six,all pegeons but six, and all ducks but six. How many birds he had in the bag in all?

cc:ebbybest,ksslib,teempakguy,llaykorn,horpeyemi18,delishpot,Engrczar, and others.