Question

A person saved rs.28750 in 10yrs. In each year after 1st year he saved rs.150 more than he did in proceeding year.The amount of money he saved in the first year was

Answer 1

Sn=28750 d=150 n=10
Sn=n/2(2a+(n-1)d)=5(2a+1350)=10a+6750
28750-6750=10a=22 a=2.2...

Answer 2

Answer: The amount he saved in first years was 2200 rupees.

Step-by-step explanation:

Let a be the amount, he saved in first year,

Since, he saved rs.150 more than he did in proceeding year,

His saving in second year = a + 150,

In third year = a + 300,

In fourth year = a + 450

............................, so on...... For 10 years,

Hence, we get an A.P, which shows his saving per year is,

a, a + 150, a + 300, a + 450, ............ Up to 10 terms,

Since, total sum = 28750,

Sum of the above A.P. = 28750

$\implies \frac{10}{2}[2a+(10-1)150]=28750$

$\implies 5(2a+1350)=28750$

$\implies 10 a + 6750 = 28750$

$\implies 10 a = 22000\implies a = 2200$

Hence, 2200 rupees are saved in first year.