kobe:

I see what you're getting at but that's not qutie the problem.
The statement is a valid one.

kobe:

The length and the width of a rectange are given by consecutive integers. The area of the rectangle is 90 cm squared . Find the length of a diagonal of the rectange.

kobe:

The following is invalid, explain why.

a = x
a+a = a+x
2a = a+x
2a-2x = a+x-2x
2(a-x) = a+x-2x
2(a-x) = a-x
2 = 1

donchichi:

lets assign the value x and x+1 to the length and breadth respectively.

Area, A = x(x+1)

90 = x(x+1) = x² + x

moving 90 to the RHS gives

x² + x - 90 = 0
(x+10)(x-9) = 0
x is either -10 or 9. -10 is impossible because its negative so x is 9cm. which means the other dimension(x+1) is 10cm

the diagonal can be gotten by pythagoras theorem. 10² +9² = diagonal²
diagonal is sqrt of 181 which gives

kobe:

A plane is spotted by 2 men who are 500 feet apart. As the plane passes over the line joining them, each man takes a sighting of the angle of elevation to the plane. The man on the far right measures an angle to be 45 degrees and the man on the far left measures an angle to be 50 degrees. How high is the plane?

kobe:

I have $11.60, all dimes and quarters, in my pocket. I have 32 more dimes than quarters. How many dimes, and how many quarters, do I have?

For non-Americans, a dime is $0.10 and a quarter is $0.25.

kobe:

Justin's parents pay him $0.50 to do the laundry and $1.25 to mow the lawn. In one month, he does the laundry 6 more times than he mows the lawn. If his parents pay him $12.75 that month, how many times did he mow the lawn?

dinozzo:

lets assume the lawn was mowed x times in a month and the laundry y times in a month. the laundry was done 6 more times than the lawn which means y=6x

he was paid $12.75 for the month which basically means: for the x times he did the lawn and 6x times he did the laundry he was paid $12.75. in mathematical terms: 0.5(6x) + 1.25x = $12.75, simplifying will give; 4.25x = 12.75; x=3

therefore he mowed the lawn thrice

kobe:

A sink can be filled in 3 mins by the cold water faucet and in 5 mins by the hot water faucet. The drain can empty the sink in 6 mins. If the drain is open, how long will it take to fill the sink with both the faucets open?

delta_v (change in volume) = dv = Vf - Vi = Vsink = V
dv1 = dv2 = V = -dv3

I was able to balance a weightless beam, ten meters long, on a fulcrum by putting a 6 kg mass on one end, and an unknown mass on the other end. To balance this, I had to place the fulcrum 1.5 meters from the 6kg mass. What is the unknown mass?

The length and the width of a rectange are given by consecutive integers. The area of the rectangle is 90 cm squared . Find the length of a diagonal of the rectange.

How many liters of a 10% solution of acid should be added to 20 liters of a 60% solution of acid to obtain a 50% solution?

mama orga:

see talent for nairaland,

na wa oooooooooooooo

make one of una volunteer to be my teacher oooooooooooo

i will be writing series of aptitude tests soon ooo

in my quest for a job

i want to pass them

am serious

someone please help me out

thanks

donchichi:

I beg to differ. The questions says he does the laundry 6 more times than he mows the lawn and not he does the laundry 6 times more than he mows the lawn. i think it should be 6 + x.

donchichi:

I beg to differ. The questions says he does the laundry 6 more times than he mows the lawn and not he does the laundry 6 times more than he mows the lawn. i think it should be 6 + x.

bawomolo:

the area of a trapezoid is less than or equal to 87cm^2.

the base(b1) of the trapezoid is 3cm less than the base(b2) of the trapezoid. the height(h) of the trapezoid is 6cm. what is the maximum value of b1 that can be achieved.


hint- b1 is between 10 and 15

a = x
a+a = a+x
2a = a+x
2a-2x = a+x-2x
2(a-x) = a+x-2x
2(a-x) = a-x
2 = 1

4Him:

Area of trapezoid = h {(b1+b2)/2}

Since b1 is 3cm less than b2 - b2 = b1 + 3
Substitute into equation . . .

6{(b1+b1+3)/2} <= 87

6b1 + 9 <= 87

Solving for b1 . . . maximum value = 13

bawomolo:

correct.

find the magnitude for the zeros of the equation x^2 -10x + 34.

this thread is fun, keep it going

4Him:

I'm stuck . . . is the answer x = 5 +/- 3i

I'm having to find the square root of a negative number.

Rasheed can mow his mother's lawn in 6 minutes. His brother Peter can mow it in 9 minutes. How long will it take them to do it together, if each has his own lawnmower.