Question 6

Find the sum of all two digit numbers which when divided by 4, yields 1 as remainder.

Answer

The two-digit numbers, which when divided by 4, yield 1 as remainder, are

13, 17, … 97.

This series forms an A.P. with first term 13 and common difference 4.

Let *n* be the number of terms of the A.P.

It is known that the *n*th term of an A.P. is given by, *a**n* = *a* + (*n* –1) *d*

∴97 = 13 + (*n* –1) (4)

⇒ 4 (*n* –1) = 84

⇒ *n* – 1 = 21

⇒ *n* = 22

Sum of *n* terms of an A.P. is given by,

Thus, the required sum is 1210.

Siddhant Saxena
2019-09-19 19:39:28

Thanks

Shivangi Mishra
2019-09-14 11:43:16

kindly try to change the background theme.

Yashraj
2019-09-06 22:21:24

Excellent

Sr
2019-07-20 16:40:28

Excellent

Preetam
2016-10-14 01:28:02

Thanks

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