Question

Mr. Dhanesh saves some amount every month. In first month he saves 400
second month 500, third month 600. etc. In which month will he save
2000? Find his total saving in 17 months.​

Answer 1

Answer:

17th month

Step-by-step explanation:

total savings =

400+500+600+700+800+900+1000+1100+1200+1300+1400+1500+1600+1700+1800+1900+2000 =20700

Answer 2

His total saving in 17 months would be ₹ 20,400.

Step-by-step explanation:

Mr. Dhanesh saves some amount every month.

In first month he saves ₹ 400, in second month ₹ 500 then ₹ 600 ....

The A.P. series would be 400, 500, 600 ......

Common difference (d) = 500 - 400 = ₹ 100

First term (a) = 400

Total numbers (n) = 17

Last term (l) = a +(n-1) × d

                    = 400 +(17-1)100

                    = 400 + 1600

                    = ₹ 2000

On 17th month he will save ₹ 2000.

Now to calculate his total savings of 17 months use the formula

$Sum=\frac{n}{2}(a+l)$

$Sum=\frac{17}{2}(400+2000)$  

     = 8.5(2400)

     = ₹ 20,400

His total saving in 17 months would be ₹ 20,400.

Learn more about A.P. series : https://brainly.in/question/14475149