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

Q: Problem: dhoni bought 5 toys with the average cost of $ 10 . if david also buys the sixth toy with the price of $ 16 , what is the average ( arithmetic mean ) price of those 6 toys ?

A: $ 1
****
Q: Problem: how many positive integers less than 20 can be expressed as the sum of a positive multiple of 2 and a positive multiple of 3 ?

A: 14
****
Q: Problem: machine a takes 50 hours to complete a certain job and starts that job at 6 am . after four hour of working alone , machine a is joined by machine b and together they complete the job at 1 pm . how long would it have taken machine b to complete the job if it had worked alone for the entire job ?

A:
3.8
****