BTGModeratorVI wrote: ↑Thu Aug 27, 2020 12:05 pm
When positive integer x is divided by 20, the remainder is 8. What is the remainder when x is divided by 5?
A. 1
B. 3
C. 5
D. 8
E. Cannot be determined
Answer:
B
Source: Veritas Prep
Another approach:
When it comes to remainders, we have a nice rule that says:
If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc.
For example, if k divided by 5 leaves a remainder of 1, then the possible values of k are: 1, 1+5, 1+(2)(5), 1+(3)(5), 1+(4)(5), . . . etc.
When positive integer x is divided by 20, the remainder is 8.
So, the possible values of x are: 8, 28, 48, 68, 88,...
Let's
test a few values
8 divided by 5 equals 1 with remainder
3
28 divided by 5 equals 5 with remainder
3
48 divided by 5 equals 9 with remainder
3
68 divided by 5 equals 13 with remainder
3
88 divided by 5 equals 17 with remainder
3
.
.
.
It certainly LOOKS like the remainder will always be
3
Answer: B
Cheers,
Brent
