Possible incorrect solution in tickbox quiz Arithmetic column 1?

[user1849]

I don’t know how the correct answer here is 18. The positive factors of 36 are 1x36, 2x18, 3x12, 4x9, 6x6 which equal to 10 and accounting for -ve factors we just multiply by 2, so we should get 20. Or are we not counting 36 as a factor of itself?

And here by the method shown we should first divide 1000 by 77 which gives us 12 and no longer divisible by 77, but the given answer is 98. Am I missing something?

[ganesh]

@user1849

I don’t know how the correct answer here is 18. The positive factors of 36 are 1x36, 2x18, 3x12, 4x9, 6x6 which equal to 10 and accounting for -ve factors we just multiply by 2, so we should get 20. Or are we not counting 36 as a factor of itself?

You might be double counting the 6 there, right?

@user1849

And here by the method shown we should first divide 1000 by 77 which gives us 12 and no longer divisible by 77, but the given answer is 98. Am I missing something?

Not quite, 77 isn’t a prime number so we ca’t just try dividing by 77. Check out the following in PrepSwift (Arithmetic column 1) and try this one again:

[user1849]

Thank you Ganesh for answering my doubts