Question

If all students of one class get to the
together and save Rs. 32 per month.
hocow many reness will be
bé collected
in 10 months?
c.​

Answer 1

first term a=32 and common difference d=36−32=4.

Let it take n months to saves Rs. 2000.

∴Sn

= 2n

[2a+(n−1)d]=2000

⇒ 2n

[2×32+(n−1)×4]=2000

⇒n[2n+30]=2000

⇒n[n+15]=1000

⇒n 2

+15n−1000=0

⇒(n+40)(n−25)=0

⇒n=−40,25

But n=-40 being negative integer is not possible.

∴n=25

Hope this helps !