Question

A sum of $ 700 is to be used to give seven cash prizes to the students of a school for their overall academic performances, If each prize is $ 20 less than its preceding prize, find the value of each of the prizes.​

Answer 1

Step-by-step explanation:

Sn=700, d=20, n=7, a=?

Sn=n/2(2a+(n-1) d)

700=7/2(2a+(7-1) 20)

1400=14a+840

560=14a

a=40

So the prizes are 40$,60$,80$,100$,

120$,140$,160$