Three friends share a flat
• al pays 30% of the rent
• bob pays 1/4of the rent
• chris pays £225
how much do they pay altogether for the rent

If Al pays 30%, and Bob pays 1/4 (which is equal to 25%), then that means that Chris pays 45% of the rent. That means they would pay 500 in total.

Rent is 500 pounds.
30% of 500 = 150 pounds for Al
25% 0f 500 = 125 pounds for Bob
and 225 pounds or 45% for Chris