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

Explanation

Let first prize be of Rs. 'a'.
Then, other prizes will be of `Rs. (a-20),Rs.(a-40),Rs. (a-60),Rs.(a-80),Rs.(a-100)` and `Rs. (a-120)`
`:. a+(a-20)+(a-40)+(a-60)+(a-80)+(a-100)+(a-120)=700`
`rArr 7a-420=700`
`rArr 7a=1120`
`rArr a=160`
`:.` Amount of prizes=Rs. `160, Rs. 140, Rs. 120, Rs. 100, Rs. 80, Rs. 60, Rs. 40.`