how ??

s/t=64.12 You're missing that part in your problem. You may wanna edit that. Anway, 64.12 is a number written in the form Q+(R)/d where Q=Quotient R=Remainder and d=divisor. Comparing to this form we get 64 is the quotient and R/d=0.12
Now, R/d=12/100=3/25

R/d=3/25
But the divisor is t which is a piece of info already given to us. So we rewrite the equation as

R/t=3/25
t=R*25/3

Now whichever value of R we plug in, we NEED to get an integer value for t.
(1)Put R=2 in t=R*25/3. We don't get an integer value so NO
(2)Put R=4 in t=R*25/3. We don't get an integer value so NO
(3)Put R=8 in t=R*25/3. We don't get an integer value so NO
(4)Put R=20 in t=R*25/3. We don't get an integer value so NO
(5)Put R=45 in t=R*25/3. We do get an integer value so YES. Hence E. Hope your clear.

i think the q is : s/t=64.12
remainder = .12*t
t is integer.
a) .12*t = 2 not integer.
b) .12*t=4 not integer
c) .12*t=8 not integer
d) .12*t=20 not integer
e) .12*t=45 -> t=4500/12 =375
IMO E

s=64, t=12, s/t=64/12=5*12 +4
b

rmazzawi wrote:If s and t are positive integers such that = 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

plz helpppp

I posted a solution here:

https://www.beatthegmat.com/number-systems-t67512.html