AnantpriyaSingh wrote:
andreagonzalez2k wrote:
x/y=1212/100
If we reduce the fraction we have
x/y=303/25
(1) 1/y is a terminating decimal
y can be 100, 50, 25, 1000... so insufficent
(2) y is a double digit odd number
if we multiply numerator and denominator by 3
303/25 = 909/75
so we have two options, insufficient
(1) and (2)
1/75 is not a terminating decimal because 75=3*25, so the only valid option is 25, sufficient
IMO C
Hey, any reason for multiplying once by 3? Is it because we need an odd number? Also why just multiplied one?
Let x and y be 2 positive integers such that x/y=12.12, what is the value of y?Given x/y = 12.12 = 303/25, this implies that y is a positive multiple of 25. Therefore, it can be 25, 50, 75, 100, and so on.
(1) 1/y is a terminating decimal.
This implies that y has only 2s and 5s in its prime factorization, so y = 25*2^n*5^m, where m and n are nonnegative integers. Hence, possible values for y include 25*2^2 = 100, 25*5 = 125, and so on. Not sufficient.
(2) y is a double digit odd number.
This implies that y can be either 25 or 75. Not sufficient.
(1)+(2) y cannot be 75 since in that case 1/y = 1/75 would not result in a terminating decimal. Therefore, the only remaining value from (2) is 25. Sufficient.
Answer: C.