The task is to generate the correct answer for a given math problem.

Problem: if x and j are integers and 2 x – j = 11 , then 4 x + j can not be
17

Problem: what is the dividend . divisor 13 , the quotient is 17 and the remainder is 1
222

Problem: a tank is filled by 3 pipes a , b , c in 3 hours . pipe c is twice as fast as b and b is twice as fast as a . how much will pipe a alone take to fill the tank ?

21 h