This is from chapter 10 of manhattan gmat prep, book 1. pg 29
When positive integer A is divided by positive integer B, the result is 4.35.
Which of the following could be the remainder when A is divided by b?
I see that .35 is part of the remainder, so solve the decimal: 35/100 = 7/20 (by reducing)
and since we know that a remainder = R/B (the divisor)
7/20 = R/B
in the book, they suggest cross multiplying - leaving us with 7B = 20R...
the answer states, that since both b and r are integers, we can see that r MUST contain a 7 in its prime factorization, otherwise there is no way for 7 to appear on the left side.
this may be silly of me to ask for some, but does this mean that b must be a multiple of 20 also? (or 2^2 and 5?) since they are equal?
a little lost...on how you figure out that the remainder must be a multiple of 7...
if anyone has any advice, input - i would really appreciate it! thanks.
When positive integer A is divided by positive integer B, the result is 4.35.
Which of the following could be the remainder when A is divided by b?
I see that .35 is part of the remainder, so solve the decimal: 35/100 = 7/20 (by reducing)
and since we know that a remainder = R/B (the divisor)
7/20 = R/B
in the book, they suggest cross multiplying - leaving us with 7B = 20R...
the answer states, that since both b and r are integers, we can see that r MUST contain a 7 in its prime factorization, otherwise there is no way for 7 to appear on the left side.
this may be silly of me to ask for some, but does this mean that b must be a multiple of 20 also? (or 2^2 and 5?) since they are equal?
a little lost...on how you figure out that the remainder must be a multiple of 7...
if anyone has any advice, input - i would really appreciate it! thanks.
