Walsh-paper 6, question 70.

[Dixon]

(16(12)3) (49(14)2)
(100(?)3)

The answer is 30, can anyone explain this? Thanks.

[Manny0311]

Bit tricky

Square root the number on the left and then multiply by number on right.

sq root of 16 is 4 X 3 = 12
sq root of 49 is 7 X 2 = 14
sq root of 100 = 10 X 3 = 30

[trampoline]

12/3 = 4 then this number squared = 16
14/2= 7 again squared =49

Therefore middle number must be 30 as divided by 3= 10 and 10x10 = 100

I think I've explained that ( to myself anyway )

[Dixon]

Many thanks to you both. I can't believe that there are many 10 year olds that will get that. Certainly not within the allocated time of the test. One of those leave it until the end and have a guess!

[Manny0311]

Many thanks to you both. I can't believe that there are many 10 year olds that will get that. Certainly not within the allocated time of the test. One of those leave it until the end and have a guess!

I've found these ones tricky..Ds sometimes gets the last one wrong in these on the paper..same with the number sequences

[hermanmunster]

Possibly the first three numbers 16 49 and 100 will ring a bell as being squares.... hopefully they get the rest fro there