Question

The sum of 2 numbers is 80. The ratio of the numbers is 3 to 5. Find the large number

Answer 1

larger : smaller = 5 : 3
larger : total = 5 : (3 +5) = 5 : 8

The total of 8 "ratio units" represents the sum 80, so each ratio unit represents 10. The larger number is 5 ratio units, so is 50.