Problem Solving

Question

As part of Joe's workout schedule, he plans to increase the number of sit-ups he does by 5 each day.  If he starts with a workout of 30 sit-ups, what is the total number of sit-ups Joe does over a 14-day period?

Answer 1

num situps=30, 35, 40,...  arithmatik progresshun

start=30, step size=5 & num "terms"=14

sum=(start + last)*n/2

last=start+(n-1)*stepsize=30+13*5=30+65=95

start+last=30+95=125

n/2=7

sum=7*125=875