Question

A man saves Rs.2600 in the 10th years of his service. In each year after the first he saved Rs.100 more than he did in the preceding year. How much did he save in first year?

Answer 1

$\huge\underline\bold{Answer}$

Let Rupees saved first year = x

So x + x+100 + x+200+x+300+x+400+x+500+x+600+x+700+x+

800+x+900 = 2600

➠4500+10x=2600

➠10x=2600-4500

➠-1900/10

➠-190

Hope it helps :)

Answer 2

$S{n}$ = $\frac{n}{2}$ [ 2a + ( n-1) d]                   [  where a= first term,

                                                     d = common difference

                                                     n = number of terms]

$S{n}$ = $\frac{10}{2}$ [ 2a + ( 10-1) × 100]

    2600 = 5 ( 2a + 9 × 100)

     2600 =5 ( 2a + 900)

    2600 = 10a + 4500

    10a = 4500 - 2600 =1900

     a = $\frac{1900}{10}$ = 190

Hence he saves Rs. 190 in first year.

Ans :-Hence he saves Rs. 190 in first year.