Question 10

The sum of all the natural numbers between 301 and 501 (including 301 and 501) which are divisible by 7 is

Solution

301 is divisible by 7 (43 times)

497 is also divisible by 7 (71 times)

So, the required sum is

7 ( 43 + 44 + .... + 71)

= 7 x (sum of numbers upto 71 - sum of numbers upto 42) = 7 * [(71x 72/2)-(42 x 43/2)]

= 11571

Create a FREE account and get:

Download RRB Study Material PDF
45+ RRB previous papers with solutions PDF
300+ Online RRB Tests for Free

CAT Quant Questions | CAT Quantitative Ability

CAT Averages Mixtures Alligations Questions CAT Quadratic Equations Questions CAT Linear Equations Questions CAT Algebra Questions CAT Time, Distance and Work Questions

CAT DILR Questions | LRDI Questions For CAT

CAT Maxima-Minima Questions CAT Coins and Weights Questions CAT Quant Based DI Questions CAT Data change over a period Questions CAT Routes And Networks Questions

CAT Verbal Ability Questions | VARC Questions For CAT

CAT Para Jumbles Questions CAT Para Summary Questions CAT Vocabulary Questions CAT Critical Reasoning Questions CAT Odd One Out Questions

Follow us on

Boost your Prep!

Download App