A bag of sweets contains only mints, sherberts and toffees.
The ratio of the number of mints to sherberts is 2:3.
The ratio of the number of sherberts to toffees is 7:5.
What fraction of the sweets are sherberts?
The Lowest Common Multiple Of 3 and 7 is 21 This means the ratio of mints:sherberts:toffees can be written as 14:21:15 The fraction of sweets that are sherberts is therefore 21/(14+21+15) = 21/50