A pear contains 30 calories more than an apple. Ten apples have as many calories as seven pears. Find the number of calories in an apple and in a pear.

Answer 1

x = cal in an apple
x + 30 = cal in a pear

10x = 7(x + 30)
10x = 7x + 210
3x = 210
x = 70

70 cal = apple
100 cal = pear