Question

a man earned 3500 the first year he worked. if he received a raise of 400 at the end of each year, what was his salary during the 15th year

Answer 1

At the start of his 15th year he has completed 14 years, so he has received 14 * 400 = 5600 in raises.

His salary during the 15th year is 3500 + 5600 = 9100

Answer 2

nuther arithmatik sequens

start=3500, step size=400, n=how many=15

last yeer=9,100

15-1=14, 14*400=5600, 5600+3500=9100