Mathematics (9-1) J560 9-1: Ratio, Proportion and Rates Of Change Topical Past Paper Questions

y is inversely proportional to $ x^{3} $. y = 4 when x = 12. Find a formula linking x and y.

Hiro invests £2500 for 2 years in a bank account paying $ r\% $ per year compound interest. At the end of 2 years, the amount in the bank account is £2704. Calculate r. $ r = $ $$ r=\dots\dots\dots\dots\dots\dots[4] $$

A bag of sweets contains jellies, mints and toffees. The ratio of jellies to mints is $n:2$. The ratio of mints to toffees is $5:3n$. Work out the ratio of jellies to toffees. Give your answer in its simplest form.