3.Mario and Kenneth work in a car wash station. The time that Mario takes inwashing a car alone is 20 minutes less than the time that Kenneth takes inwashing the same car. If both of them work together in washing the car, it willtake them 90 minutes. How long will it take each of them to wash the car?


Can you paste here the solution and how you get it for a proof thanks in advance ^^^^

1

Answers

2014-08-12T07:05:55+08:00
Let m=Mario, k=kenneth

m+k=90

m=k-20

Sol'n for k
m+k=90
(k-20)+k=90
k-20+k=90
k+k-20=90
2k-20=90
2k=90+20
2k/2=110/2
k=55

Sol'n for m
m=k-20
m=(55)-20
m=35

Checking
m+k=90
35+55=90

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