Question

Three students use pens to write th enams of graduating seniors on thei rdiplomas. One writes 7 names in 6 minutes, another writes 17 names in 10 minuts, and the third writes 23 names in 15 minutes. How long, to the nearest minute, will the students take to the write the names on 440 diplomas if they work together?

Answer 1

Total time ≈ 100(nearest minutes)

Explanation:

The rates at which each student writes names per minutes can be calculates as follows.

First student

6 minutes = 7 names

1 minute = 7/6 names

second student

10 minutes = 17 names

1 minute = 17/10 names

Third student

15 minutes = 23 names

1 minute = 23/15 names

Total time = 440/total rate

Total time = 440/1.17 + 1.7 + 1.53

Total time = 440/4.403

Total time = 99.931

Total time ≈ 100(nearest minutes)