send mail to support@abhimanu.com mentioning your email id and mobileno registered with us! if details not recieved
Resend Opt after 60 Sec.
By Loging in you agree to Terms of Services and Privacy Policy
Claim your free MCQ
Please specify
Sorry for the inconvenience but we’re performing some maintenance at the moment. Website can be slow during this phase..
Please verify your mobile number
Login not allowed, Please logout from existing browser
Please update your name
Subscribe to Notifications
Stay updated with the latest Current affairs and other important updates regarding video Lectures, Test Schedules, live sessions etc..
Your Free user account at abhipedia has been created.
Remember, success is a journey, not a destination. Stay motivated and keep moving forward!
Refer & Earn
Enquire Now
My Abhipedia Earning
Kindly Login to view your earning
Support
Type your modal answer and submitt for approval
What is the sum of digits of the least number, which when divided by 15, 18 and 42 leaves the same remainder 8 in each case and is
also divisible by 13?
24
26
25
22
- We need the smallest number that leaves a remainder 8 when divided by 15, 18, and 42, and is also divisible by 13.
- Such a number is of the form: N = LCM(15, 18, 42) × k + 8, where k is a positive integer.
- LCM(15, 18, 42) = 630.
- So, N = 630k + 8, and N is divisible by 13.
- N = 630k + 8 = 0 (mod 13)
630 mod 13 = 5 (because 13×48 = 624, 630-624=6, correction)
Wait, so 13×48 = 624, 630 - 624 = 6 ? so, 630 = 6 (mod 13)
So, 630k + 8 = 0 (mod 13) ? 6k + 8 = 0 (mod 13)
6k = -8 = 5 (mod 13) (since -8 mod 13 = 13-8 = 5)
Find k: When is 6k = 5 (mod 13)?
Let's try values of k:
- k=1: 6×1=6 (mod 13)=6
- k=2: 12 (mod 13)=12
- k=3: 18 (mod 13)=5
- So k = 3 gives the smallest positive integer solution.
So N = 630×3 + 8 = 1890 + 8 = 1898
- Sum of digits of 1898 = 1+8+9+8 = 26
- Option 2 (26) is correct.
Option:2, 26 (Correct Answer)
By: santosh ProfileResourcesReport error
Access to prime resources
New Courses