Martin Saves $5 on the First Day of a 40-Day

Multiple Choice

Martin saves $5 on the first day of a 40-day period, $10 on the second day, and so on. For the next 40 days, he increases the amount saved by $10 each day (instead of $5 each day) . How much will he have saved after 80
Days?

A) $20,400
B) $20,600
C) $20,200
D) $20,300