Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 62)

Numbers

62.

(51 + 52 + 53 + ... + 100) = ?

2525

2975

3225

3775

Answer: Option

Explanation:

S_n = (1 + 2 + 3 + ... + 50 + 51 + 52 + ... + 100) - (1 + 2 + 3 + ... + 50)

=	100	x (1 + 100) -	50	x (1 + 50)
	2		2

= (50 x 101) - (25 x 51)

= (5050 - 1275)

= 3775.

Discussion:

18 comments Page 2 of 2.

NP said: 7 years ago

Here, n is number of turns
this ex. is (51 to 100 then n is 50 number).

Khemsingh gurjar jaisingh said: 7 years ago

Solved 50/2(51+100).
=25*151,
=3775 [n/2=50/2=25.

(2)

Tanya Mazumdar said: 1 decade ago

Thanks for the right and easiest technique.

Janardhan jada said: 4 years ago

Thanks to all for explaining the answer.

Prithvi said: 6 years ago

Thanks all for explaining the answer.

Kinal said: 4 years ago

Thank you everyone for explaining.

(3)

Tanisha Rajak said: 4 years ago

Thanks guys for explaining this.

Kishor said: 4 years ago

Thank you for explaining @Pooja.

(2)

Post your comments here:

Quick links

Quantitative Aptitude

Verbal (English)

Reasoning

Programming

Interview

Placement Papers