Answer: 6.56hours.
Step-by-step 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.
The multiplicative inverse of -2/5 is -5/2
