The Tree Problem

Question

1. The Tree Problem:

Chuck planted an unusual orange tree one afternoon. It came with 4 oranges on it and the number of oranges on the tree doubles each morning. Chuck, upon returning home for lunch each day, picks and eats 3 oranges for his lunch.

Fred has an unusual grapefruit tree. Each morning four more grapefruits grow on the tree. His family picks and eats 6 grapefruits at lunchtime.

How many grapefruits were on Fred's tree in the morning on the day Chuck planted his tree, if on the tenth day ( in the morning ) the number or oranges and grapefruits, on both trees, were exactly the same?

Answer 1

orange

start 4

8

5

day 2 10

7

day 3 14

11

day 4 22

19

day 5 38

35

day 6 70

67

day 7 134

131

day 8 262

259

day 9 568

565

day 10 1130

1127

1127 - 2*10 = 1107