If an 8-digit number 1a9759b0 is divisible by 108, then the maximum value of (7a + 3b) is:

This question was previously asked in
CRPF Head Constable Ministerial Official Paper (Held On: 24 Feb 2023 Shift 2)
View all CRPF Head Constable Papers >
  1. 66
  2. 81
  3. 72
  4. 60

Answer (Detailed Solution Below)

Option 1 : 66
Free
CRPF Constable (Technical & Tradesmen) Full Mock Test
91.9 K Users
100 Questions 100 Marks 120 Mins

Detailed Solution

Download Solution PDF

Given:

The 8-digit number is 1a9759b0.

The number is divisible by 108.

108 = 4 × 27

Formula Used:

Divisibility rule of 4: The number formed by the last two digits must be divisible by 4.

Calculation:

For divisibility by 4, the last two digits 'b0' must be divisible by 4. Possible values of b are 0, 2, 4, 6, 8.

Taking b = 8 for maximum value of  (7a + 3b).

Now the number is: 1a975980

Sum of each digit = 1 + a + 9 + 7 + 5 + 9 + 8 + 0 = 39 + a

Since a is since digit number, 39 + a must be divisible by 9.

39 + a = 45

a = 6

Maximum value of (7a + 3b) = (6 × 7 + 8 × 3)  = 66

The maximum value of (7a + 3b) is 66.

Latest CRPF Head Constable Updates

Last updated on Jun 11, 2024

-> CRPF Head Constable 2024 Detailed Notification has been released!

-> A total of 282 vacancies have been announced for both Male and Female candidates.

-> Interested candidates can apply online from 9th June to 8th July 2024. 

-> The selection process includes a Computer-Based Test, Skill Test, Physical Standard Test (PST), Document Verification, and Detailed Medical Examination (DME).

-> Refer to CRPF Head Constable Previous Year Papers here!

Get Free Access Now
Hot Links: lotus teen patti real teen patti teen patti classic