Question

A company contracts to paint 3 houses. Mr. Brown can paint a house in 6 days while Black would take 8 days and Blue 12 days. After 8 days Brown goes on vacation and Black begins to work for a period of 6 days. How many days will it take Blue to complete the contract?

Answer 1

You can start with the equation of
(1/6)x8+(1/8)x6+(1/12)x X=3

Multiply by common denominator of 24 to get
32+18+2x=72

Simplify it we get
50+2x=72

Eliminate using algebra (because it’s add 50 take away the 50 on both sides)
2x=22

Because it’s X2 divide by 2 on both sides
x=11
It will take 11 days