A sum of Rs 700 is to be used to give seven cash prizes to students of – InterviewSolution

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1.	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.
Answer» Here, we are given, `S_7 = 700, n = 7 and d = -20` We know,`S_n = n/2(2a+(n-1)d)` `700 = 7/2(2a+6(-20))` `200 = 2a-120=>a = 320/2 = 160` So, `a_1 = 160` `a_2 = 160-20 = 140` `a_3 = 140-20 = 120` `a_4 = 120-20 = 100` `a_5 = 100-20 = 80` `a_6 = 80-20 = 60` `a_7 = 60-20 = 40` So, value of each of the prives will be, `160,140,120,100,80,60,40`

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