Question

Lucy can assemble a computer​ by herself in 35 minutes. Manny does the same job in 50 minutes. How long will it take them to assemble a computer working together?

Answer 1

Answer:

Step-by-step explanation:

I think its 15 I just subtracted the two numbers

Answer 2

Answer: about 20.6 minutes

Step-by-step explanation:

Given : Lucy can assemble a computer​ by herself in 35 minutes.

Manny does the same job in 50 minutes.

Let t be the time taken by both of them working together.

Then, we have

$\dfrac{1}{t}=\dfrac{1}{35}+\dfrac{1}{50}\\\\\Rightarrow\ \dfrac{1}{t}=\dfrac{35+50}{35\times50}\\\\\Rightarrow\ \dfrac{1}{t}=\dfrac{85}{1750}\\\\\Rightarrow\ t=\dfrac{1750}{85}=20.5882352941\approx20.6$

Hence, it will take approx 20.6 minutes to assemble a computer working together.