Could anyone explain the answer details?

Hi robin:

For these types of questions, I would focus on the decimal part since it signifies the remainder.

Now we have decimal part = 0.45 = 45/100; lets reduce it to the simplest fraction form:

45/100 = 9/20. Therefore we know that when one of the INTEGERS "a" is divided by "b"; remainder is a multiple of 9 (the numerator). Now just look for the number which is NOT a multiple of 9. [spoiler](3 is the correct answer).[/spoiler]

Let me know if this helps

Anurag@Gurome wrote:

rrobiinn wrote:a and b are integers such that a/b =3.45. If R is the remainder of a/b, which of the following
be could NOT be equal to R?

(A) 3
(8) 9
(C) 36
(D) 81
(E) 144

Say, when a is divided by b, the quotient is x.
Hence, a = bx + R

But, a/b = 3.45 => a = 3.45b = 3b + .45b

As a, b and R are integers, comparing the terms, x must be equal to 3 and R must be equal to 0.45b.

Hence, for b to be integer, (R/0.45) must be an integer.
For R = 3, (R/.45) is not an integer, i.e. 3 cannot be a value of R.

The correct answer is A.

One of the best explanations for beginners.
Thanks.