The cost of a car is 400% greater than the cost of a bike. If there is an increase in the cost of the car is 15% and that of bike 20%. Then the total increase in the cost of the 5 cars and 10 bikes is:

Explanation:-

Let the bike's initial cost be X and then car's initial cost be 5X.
After the increase,
Bike price = 1.2X
Car price = 5.75X
Initial total cost of 5 cars and 10 bikes,
= 25X+10X = 35X
New cost,
= 28.75X+12x = 40.75X
Change in cost = (40.75X-35X) = 5.75X
% change = (5.75X*100)/35 = 16(3/7)%.