First one: 2/3 of an hour is 40 minutes
every 10 minutes he finishes 1/7 of the car.
so about 70 minutes
Second one:
2in=1.5kilo
2.5kilo=?
1.5/2=.75
so every 1 inch is .75 kilos
2.5 kilo / .75 kilo = 3.33
so it would take 3.33 inches to get 2.5 kilo
and the last one is just 5(.75) which is 3.75
because if 1 inch = .75 kilo you'd just have to multiply .75(5).
