Question

A firm advertises for workers to address envelopes. Priscilla says she will work 100 hours. Herb will work for 80 hours. If each can address 10,000 envelopes in the time they work, how long would it take them to address 10,000 envelopes if they work together?

Answer 1

I'm guessing 90 hours because if you add their hours together it'll be 180 if they work together it'll be like half the time which is 90