Which 3 working together could sort 1000 letters in 2 hours?

Question

Mike can sort 400 letters in 2 hours

Pat can sort 450 letters in 3 hours

Andrew can sort 400 letters in 4 hours

Shauna can sort 500 letters in 2 hours

Which 3 working together could sort 1000 letters in 2 hours?

Answer 1

Mike: 200 / hour

Pat: 150 / hour

Andy: 100 / hour

Shauna: 250 / hour

Can you determine the answer now?

Answer 2

Mike can sort 400 letters in 2 hours, or 200 letters in 1 hour.

Pat can sort 450 letters in 3 hours, or 150 letters in 1 hour.

Andrew can sort 400 letters in 4 hours, or 100 letters in 1 hour.

Shauna can sort 500 letters in 2 hours, or 250 letters in 1 hour.

Since we want them to work in 2 hours,

Mike: 400 letters / 2 hours

Pat: 300 letters / 2 hours

Andrew: 200 letters / 2 hours

Shauna: 500 letters in 2 hours.

Now, which of these three can we add together to reach a sum of 1000 letters sorted in 2 hours?

Pat + Andrew + Shauna = 300 + 200 + 500 = 1000 letters in 2 hours.