Question

Heraldo starts a push-up challenge, and on the first day does 10 pushups, the second day he does 13, the third day he does 16, and so on.

Write the recursive definition for this sequence, and then find how many pushups he should do on the 20th day, if he continues.

Answer 1

Day 20 = 67 pushups (64+3)

Explanation:

Day 1 = 10 pushups Day 2 = 13 pushups (10+3) Day 3 = 16 pushups (13+3)

He does three more pushups each day.

So day 4 = 19 pushups (16+3)

Day 5 = 22 pushups (19+3)

Day 6 = 25 pushups (22+3)

Day 7 = 28 pushups (25+3)

Day 8 = 31 pushups (28+3)

Day 9 = 34 pushups (31+3)

Day 10 = 37 pushups (34+3)

Day 11 = 40 pushups (37+3)

Day 12 = 43 pushups (40+3)

Day 13 = 46 pushups (43+3)

Day 14 = 49 pushups (46+3)

Day 15 = 52 pushups (49+3)

Day 16 = 55 pushups (52+3)

Day 17 = 58 pushups (55+3)

Day 18 = 61 pushups (58+3)

Day 19 = 64 pushups (61+3)

Day 20 = 67 pushups (64+3)