Question

Jenna can paint the shed in 2 hours. Juan can paint it in 1.5 hours. • Jenna says is they work together the job will take 1/2+1/1.5=1^1/2 hours. • Juan says if they work together the job will take 2+1.5/2=1^3/4 hours. Determine if either Jenna or Juan is correct. Explain your reasoning with numbers and words.

Answer 1

There is a formula for this:

[Worker 1 Time * Worker 2 Time] / [Worker 1 Time + Worker 2 Time]

[2 * 1.5] / [2 + 1.5] = 3.0 / 3.5

= 0.8571428571 Hours =

51.43 minutes

Both Jenna and Juan are INCORRECT.

Explanation:

Answer 2

Explanation:

1 job / 2 hours + 1 job / 1.5 hours = 1 job / x When they work together.

1/2 + 1/1.5 = 1/x Basic Equation. Change to decimal form

0.5 + 0.6666 = 1/x Add like terms on the left

1.1666666 = 1/x Multiply by x on both sides.

1.1666667 x = 1 Divide by 1.16666667

x = 1 / 1.166667 Do the division.

x = 0.8571428

x = 6/7 of an hour.

This kind of question will always produce an answer that is less than the smallest number.

So the answer must be smaller than 2 hours or 1.5 hours.