Question

A student saves money for the purpose of school trip. He gives the money to his teacher in the form of AP. He pays ₹110 and ₹210 in 5th and 6th week. In this way how many weeks are required to accumulate a sum of ₹1680.

Answer 1

Answer:

$sn = n \div 2(2a + (n - 1)d)$

a=110

d=100

Sn=1680

Explanation:

By putting the values we get

50n2+60n-1680

By middle term splitting find n