If n is a positive integer and r is the remainder when 4 + 7n is divided by 3, what is the value of r?
a. n+1 is divisible by 3
b. n>20
a. n+1 is divisible by 3
b. n>20
OA is A?
1) n + 1 is divisible by 3 = 3,6,9 etc. n is 2,5,8 etc
n=2 --> 4 + 7n = 4 + 7*2 = 18 . now as n increases the numbers keep adding 21 to itself ( for eg. n =5 --> 4 + 7n =39 etc.... ) So it always leaves the same remainder (0 in this case.)
2) n > 20. for different ns we can get diff values and remainders. hence not sufficient.
