If a heater consumes 6 units of electricity in 2 ½ HOURS. How many units will be consumed in 10 hours? (b) For how many hours will the heater run on 15 units?

Question

Direct and inverse proportion

Answer 1

10 hours is 4 times as long as 2½ hours so the heater will consume 4 times as much in 10 hours as it does in  2½ hours=6*4=24 units.

It takes (15/6)*(5/2) hours to consume 15 units=(5/2)*(5/2)=25/4=6¼ hours.