1 Trent can deliver his newspapers in 20 minutes It takes Lo

1. Trent can deliver his newspapers in 20 minutes. It takes Lois 60 minutes to do the same route. How long would it take them to deliver the newspapers if they worked together? It will take____minutes.

2. How many gallons of a 90% antifreeze solution must be mixed with 60 gallons of 30% antifreeze to get a mixture that is 80% antifreeze. The number of gallons that must be mixed is____gallons.

Solution

1.
In 1 minute, Trent can deliver 1/20 newspaper
In 1 minute, Lois can deliver 1/60 newspaper

Together in 1 minute, they can deliver, (1/20) + (1/60) part = 4/60 part = 1/15 part
To deliver all newspaper they will together take 15 minutes
Answer: 15 minutes

I am allowed to answer only 1 question at a time