Question

Find the AP. whose 1st term is 100 and the sum of the 1 six terms is 5 times the sum of the next six
terms.
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Answer 1

Answer:

AP series with a = 100, d= -10

Explanation:

first term a=100

sum of first 6 terms = X = a+a+D+a+2d+a+3d.. = 6a+15d

sum of next 6 terms = y = 6a +51d

6a+15d = 5*(6a+51d)

-24a = 240d

d = -a/10 = -100/10 = -10