Question

frankie can build a speaker box in 120 minutes trash can build a speaker box 40 minutes faster if they work together how many minutes does it take them to build the speaker box

Answer 1

9514 1404 393

Answer:

48 minutes

Explanation:

Each minute, F can build 1/120 of a speaker box, and T can build 1/80 of a speaker box. Working together, in 1 minute, they can complete ...

1/120 + 1/80 . . . . . speaker boxes

= 2/240 +3/240 = 5/240 = 1/48 . . . . speaker boxes

Then there will be 1 complete speaker box after 48 minutes.