Answer:
17.78 minutes
Step-by-step explanation:
Given that;
It takes 12 liters of petrol to our  to race 8 go-karts for 20 minutes at a costs of £1.37 per liter, form a table as;
Liters of petrol     go-kart races   minutes     cost per minute
12 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 8 Â Â Â Â Â Â Â Â Â Â Â Â 20 Â Â Â Â Â Â Â Â Â 1.37
18 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 6 Â Â Â Â Â Â Â Â Â Â Â Â ? Â Â Â Â Â Â Â Â Â Â Â 1.37
Perform cross-product as;
=12*8*20*1.37)/18*6*1.37
=2630.4/147.96
=17.78 minutes
