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
Get AI Help
Create a FREE account and get:
- Download RRB Study Material PDF
- 45+ RRB previous papers with solutions PDF
- 300+ Online RRB Tests for Free
Book Free CAT Mentorship
Get personalized CAT strategy from a 99%iler
500+ students mentored
OTP Verification
Enter the 6-digit code sent to your phone
Booking Summary
Session:Free CAT Mentorship
Phone:
Date:
Time:
Enter OTP
Didn't receive the OTP?
