Question

Sachin invested in national saving certificate scheme in the first year he invested rupees 5000 in the second year rupees 7000 in the third year rupees 9000 and so on find the total amount that he invested in 12 years

Answer 1

Answer:

192000

Step-by-step explanation:

Sachin invested in first year = 5000

He invested in second year = 7000

he invested in third year = 9000

And so on

So, sequence becomes : 5000,7000,9000,......

So, a = first term = 5000

d = common difference = 7000-5000=9000-7000 =2000

Now we are supposed to find find the total amount that he invested in 12 years

So, Formula of sum of n terms in AP = $\frac{n}{2} (2a+(n-1)d)$

Now substitute n =12

So total amount he invested in 12 years :

= $\frac{12}{2} (2(5000)+(12-1)2000)$

= $192000$

Thus the total amount that he invested in 12 years is 192000