Question

If a divided by 7 has a remainder of 6, what is the remainder when 4a is divided by 7?

Answer 1

I will assume that the least number you're asking for is a positive number.
Then we have to find the smallest positive integer n that satisfies the simultaneous system of congruences
n = 4 mod 7,
n = 5 mod 8,
n = 6 mod 9

Answer 2

the correct answer is 3 hope i can answer more of your questions ={)