Question 190060
D=RxT, so T=D/R ___ the times are the same (equal)


25 / (20 + c) = 15 / (20 - c)


"cross" multiplying ___ 500 - 25c = 300 + 15c


adding 25c - 300 ___ 200 = 40c


dividing by 40 ___ 5 = c