divisibility and remainders -- HELP!

[kn2130]

I keep running into this type of problem and am unsure about the best approach to solve these questions (all the explanations I find are different, and its getting confusing)

If m and n are positive integers such that m/n = 13.24, which of the floowing could be be the remainder when m is divided by n? a) 12 b)16 c)30 d)48 e)120 answer:B

When positive integer x is divided by positive integer y, the remainder is 9. if x/y = 96.12, what is the value of y? a) 96 b) 75 c)48 d)25 e) 12 answer:B

Is s and t are positive intergres such that s/t = 64.12, which of the following could be the remainder when s is divided by t? a) 2 b)4 c)8 d)20 e) 45 answer:e

If a and b are positive integers such that a/b = 2.86, which of the following must be a divisor of a?

a)10 b) 13 c) 18 d) 26 e) 50 answer: 13


Thanks so much!

[papgust]

Use spoilers when you post the answers.

The concept is pretty simple. All four problems revolve around a single formula,

Dividend = Divisor*quotient + remainder
OR
Dividend/Divisor = quotient + remainder/divisor

Coming to the problems,

The first question should read as,

If m and n are positive integers such that m/n = 13.24, which of the floowing could NOT be the remainder when m is divided by n? a) 12 b)16 c)30 d)48 e)120

m/n = 13.24

0.24 represents the remainder here. Transform this into a fraction and simplify.

m/n = 13 + 24/100

m/n = 13 + 6/25

Here, 6/25 is of the form remainder/divisor.

r/d = 6/25

25*r = 6*d

r must be a multiple of 6 so that remainder evenly divides 6*d. All options except B are multiples of 6. So, its B


Other problems are already discussed in this forum. Also, all these problems are exactly the same as the 1st problem.
https://www.beatthegmat.com/remainder-pr ... 20246.html
https://www.beatthegmat.com/difficult-t15709.html#65825
https://www.beatthegmat.com/divisor-of-a-t37310.html

[kn2130]

Thank you so much! This was SO helpful! By the way, how do I use spoilers?

[papgust]

Check this!