Question: a and b together can do a work in 4 days . if a alone can do it in 14 days . in how many days can b alone do it ?
A) 10
B) 6
C) 77
D) 55
E) 21
Correct answer: b
Grade: 7 | Topic: Ratios and proportions | Difficulty: Easy | Standard: 7.RP.A.3