Question

a man repays alone rupees 250 by paying 20 rupees in the first month and then increase the payment by a 15 every month how long will it take him to clear the loan

Answer 1

Answer:

Step-by-step explanation:

a=20

d=15

an=250

an=a+(n-1)d

250=20+(n-1)15

250-20=(n-1)15

230=(n-1)15

230÷15=n-1

10.60=n-1

n=10.60+1

n=11.60 months or 11months 6 days.

HOPE THIS HELPS U!!

Answer 2

Answer:

Its a problem of arithmetic progression.

first term is 20. common difference is 15. sum of all terms is 250.

so the AP looks like

20,20+15,20+15+15,.......

writing the sum to n terms

a1+a2+a3+......an=Sn

a1=20, d=15

NOW,formula is

Sn=n/2(2a1+(n-1)d)

250=n/2(2*20 + (n-1)15)

500=n(40+15n-15)

form the quadratic equation and solve for n. which comes out to be 5.

15n²+25n-500=0

3n²+5n-100=0 ( divide throughout by 5)

on solving

n=5.answer

Step-by-step explanation: