moghulis:
[a×(a–1)]+(a–2), =a²–2
OR
(a×b)+(b–1) where b=a–1, =ab+b–1


Using a²–2, we have
3³–2= 9–2=...7
5²–2= 25–2=...23
7²–2= 49–2=...47
9²–2= 81–2=...79


So
10²–2= 100–2=...98
OR
USING ab+b–1
(10×9)+9–1,=90+9–1=...98

moghulis:
[a×(a–1)]+(a–2), =a²–2
OR
(a×b)+(b–1) where b=a–1, =ab+b–1


Using a²–2, we have
3³–2= 9–2=...7
5²–2= 25–2=...23
7²–2= 49–2=...47
9²–2= 81–2=...79

So
10²–2= 100–2=...98
OR
USING ab+b–1
(10×9)+9–1,=90+9–1=...98

Proudlyngwa:
How soon can you answer this

I don't know if this has been posted on nairaland before, saw it and decided to share.

Oyehomie:
The answer will be 100....
@ Proudlyngwa

zoneboy:


71

PaperLace:

Lol...nice, but we won't be using formula 1.

If you quote Formula 1 for me in your attempted solution, I will give you half mark . 'cos the numbers in the second column are there for a reason. Let's stick to formula 2.

Proudlyngwa:

Wrong bro

Modified.







For those quoting me.
Try to think of this as a riddle not an equation






























The answer is the sum of the 'product of the numbers' and the 'descending number after the numbers used'.


99 does not qualify, because even though adding upward products of 8(starting from 16) to the numbers on the right, it is not a cyclic trick question and therefore can not exist independently. i.e it must correspond with the left, if we follow the numbers on the left downwards, a pattern of 2 generates, unfortunately when it gets to 10 it is reduced to 1,making the pattern on the right invalid.

SmartyPants:


wrong. your solution does not explain the first equation since there was no preceding number. The 1 that was used there would have to have been arbitrarily chosen. A better solution that holds true in all cases is simply that you multiply the first two columns and then add to their product, the next odd, positive number to the one previously used. That is why it starts with 1.

Proudlyngwa:



Did you miss this.

The answer is the sum of the 'product of the numbers' and the ' (DESCENDING NUMBER) after the numbers used'

SmartyPants:


its not the "descending number after the number used"...its the next odd number in an arithmetic progression starting from 1...it just happens to be same as the "descending number after the number used", but that is part of the trick.

here is the test: if you use your solution, it breaks the progression, however if you apply mine, the pattern is maintained.

botad:
Ask any ABU graduate you see around. Dino first!

lammsohiman:
101

visiondee:
The answer is 99 with proof

3×2=6+1=7
5×4=20+3=23
7×6=42+5=47
9×8=72+7=79
10×9=90+9=99
Hence the proof. Show me likes if I'm right

biafranbaby:


Very good.

I almost lost hope after the first page.

Thanks Satan knowledge still abounds.

joyjonathan:
Is 99 cos it is addition of odd numbers serially i.e 1,3,5,7 and 9. In another way round after the first one which is added to,the others are addition of 2 i.e if the first on is 1,next is addition of 1+2=3, 3+2=5,5+2=7 and 7+2=9.

olumose001:
na Wa o... Answer is 108!! No correct answer in five pages... Nairalanders!!!!

GogobiriLalas:
6yrs for secondary school I no fit answer dis kine wahala...you come say make I do am for 10secs. OP no get chill at all