The length of a rectangular box is 50 and the breadth is 30 find the total area

This race was first held in 1953 on august 16th. every decade the race finishes with a festival. how many years is this?

If the scale factor between two circles is 2x/5y what is the ratio of their areas?

Prove that 16^4-2^13-4^5 is divisible by 11.