Question

Of the following series of partial sums which might arise in the addition of 36 and 25, the one that is incorrect is:
A) 11, 31, 61
B) 11, 4, 6, 61
C) 11, 41, 61
D) 36, 56, 61

Answer 1

I might be missing something with this question, but looking at it, it seems like it's asking which set of numbers cannot be made from a linear combination of 36 and 25. If that's the case, then *all* of them can be made so none would be incorrect.

Since 36 and 25 share no common factors, you can always get to 1 using a linear combination. In this case, 13(25)-9(36)=1.

From here, you can construct any other number by "scaling" up the multiples of 25 and 36.

I'm probably way off base here since that doesn't answer the question. But that's my 2-cents.