Question

Melissa exercises for 20 minutes every day. She decides to increase her daily exercise time by 5 minutes each week. However, according to her doctor’s orders, she can spend no more than 45 minutes a day exercising. For how many weeks can Melissa increase her exercise time this way?

Answer 1

this is an arithmetic sequance whose general term is 20 + 5(n - 1)
so we can write 45 = 20 + 5(n-1)
now solve for n:-
5n - 5 = 25
5n = 30
n = 6

So number of weeks she can increase = 6

Answer 2

She can only increase her exercise time for 5 weeks. The first week would be 25 the next would be 30 the third week would be 35 the fourth would be 40 and finally the fifth week would be 45, which is her limit.