Question

The table shows how the number of sit-ups marla does each day has changed over time. at this rate how many sit-ups will she do on day 12? Explain your steps in solving this problem
day 1 day 2 day 3 day 4 day 5
17 21 25 29 33

Answer 1

The number of situps form an AP with first term (a) = 17 and common difference (d) = 4

Tn = a + (n - 1)d
T12 = 17 + (12 - 1) x 4 = 17 + 11(4) = 17 + 44 = 61

Therefore, she will do 61 situps on day 12.

Answer 2

From the given table above, it shows that males sit ups each day has changed over time, and every day, the difference is 4 sit ups. There is a consistent change in her everyday routine. Therefore, since from day 5, her sit ups is 33, day 6 to 12 will be added 4 sit ups per day. Day 6 would be 37, day 7 is 41, day 8 is 45, day 9 is 49, day 10 is 53, day 11 is 57 and therefore, day 12 is 61. So Marla will have 61 sit ups on the 12th day.