Ainsley has decided to begin a 5-day sit-up challenge where she plans

1.	Ainsley has decided to begin a 5-day sit-up challenge where she plans to increase the number of sit-ups completed each consecutive day by the same amount to gradually build up her core muscle strength.After talking with a friend who already began the challenge, she's aware that she needs to complete 20 sit-ups on Day 1 of the challenge and will complete 36 sit-ups on the last day, Day 5.
Answer» Step-by-step explanation: this progression is an EXAMPLE of an AP given a=20, l=56, n=5 so, $l = a + (n - 1)d$ where d is the increase in no. of Sit UPS per day so, $56 = 20 + (5 - 1)d$ or $36 = 4d$ or $d = 9$ so, common DIFF =d=9 no. of sit-up on day 2 $a + (n - 1)d = 20 + (2 - 1)9$ $= 20 + 9 = 29$ so, no. of sit-up on day 15=20+(15-1)9 =20+126=146 sorry I could not give you the third answer. actually, the pic is BLURRED. and so, it could not be understood by me. please mark me as the brainliest