A faucet drips 2/5 gallon of water in 3 1/2 hours. What is the unit rate of water dripped per hour?

Unit rate = 4/35 of a gallon per hour

Work Shown:

3 & 1/2 = 3 + 1/2

3 & 1/2 = 6/2 + 1/2

3 & 1/2 = (6+1)/2

3 & 1/2 = 7/2

The faucet drips 2/5 of a gallon in 7/2 hours

2/5 gallon : 7/2 hours

2*(2/5 gallon) : 2*(7/2 hours) multiply both sides by 2

4/5 gallon : 7 hours

(1/7)*(4/5 gallon) : (1/7)*(7 hours) ... multiply both sides by 1/7

4/35 gallon : 1 hour

The unit rate is 4/35 of a gallon per hour.

"Per hour" means "every 1 hour".

the two may have that, even a breakdown is probably offered