Q380
If m and n are positive integers, then the digit in the unit's place of 5n + 6m is always :
A.
1
AnswerB.
5
C.
6
D.
n + m
Answer: Option A
Solution
Answer: Option A
Solution:
In 5n we have 5 as unit digit and in 6m we have 6 as unit digit.∴ 5 + 6 = 11(i.e unit digit always be 1)