Question

Mario and Julio are working together to detail cars. When they work together, they can wash7 cars in 2 hours. If mario works alone, her can detail 5 cars in 3 hours. If Julio works alone, how long would it take him to detail 12 cars?

Answer 1

Answer: 6.56hours.

Explanation:

Given;

Mario and julio can wash 7 cars in 2hours

While only mario can wash 5 cars in 3hours

Let m represent the rate at which mario work

j represent the rate at which julio work

t represent the rate at which mario and jolio combined work.

t = m + j

j = t -m .......1

t = 7 cars per 2hours = 7/2 = 3.5cars/hour

m = 5 cars per 3hours = 5/3 = 1.67cars/hour

From eqn 1

j = t -m = 3.5 - 1.67 = 1.83cars/hour

So, to determine the number of time it will take julio to detail 12 cars

Where = number of cars detailed

N = rate × time = j × time

time = N/j

time = 12/1.83

time = 6.56 hours

Therefore, it will take julio to detail 12 cars is 6.56 hours.