Lionel bought 10 oranges and 11 grapefruits.
6 oranges cost $3.
1 orange would cost $3/6
10 oranges would then cost $3/6 * 10 = $5.
3 grapes cost $2.40.
1 grape would cost $2.4/3
11 grapes would then cost $2.4/3 * 11 = $8.8.
Total amount spent = $5 + $8.8 = $13.8