Algebra Puzzle – Challenge 44

Challenge:

Edward can finish (40%) of a job in 2 days and Emanuel can finish (15%) of the same job in 3 days. How many days does it take Edward and Emanuel to finish (75%) of the same job if they work together?

A- 2.5

B- 3

C- 4.5

D- 5

E- 5.5

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Edward can finish (40%) of a job in 2 days. Therefore, he can finish the job in 5 days.
(40%) of x = 2 → x = 5
Emanuel can finish (15%) of the same job in 3 days. So, he can finish the whole job in 20 days.
(15%) of x = 3 → x = 20
First, let’s find the time it takes to finish the job if both Edward and Emanuel work together.
(frac{1}{a} + frac{1}{b} = frac{1}{t} → frac{1}{5} + frac{1}{20} = frac{1}{t} →frac{5}{20} = frac{1}{t} → t = 4)
It takes 4 days to finish the job if both of them work together. Therefore, they can finish (75%) of the job in 3 days:
(x = 4 → 75%) of x equals 3.

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