Question 165572
jean types at a rate of 1/2 page per minute 20/40
Jim  types at a rate of 2/3 page per minute 20/30

together: would be 1/2t+2/3t=20 where t is time.

find a common denominator and you get 7/6t=20 multiply both sides by 6 and you get 7t=120  so t=appx 17.1 minutes