Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8

Q.

The number of 7-digit numbers the sum of whose digits is even is

see full answer

High-Paying Jobs That Even AI Can’t Replace — Through JEE/NEET

🎯 Hear from the experts why preparing for JEE/NEET today sets you up for future-proof, high-income careers tomorrow.
An Intiative by Sri Chaitanya

a

35  ×   105

b

45  ×   105

c

50  ×   105

d

None of these 

answer is B.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

Concept- The total number of 7-digit numbers that can exist must be determined. Permutations of the numbers that can be in each digit place can be used to find this. The entire number of 7-digit numbers is even divided by the numbers with the sum of the digits.
There are seven locations in a seven-digit number. Numbers from 0 to 9 may be used in each of the seven locations aside from the first digit. The numbers other than 0 can be used in the place of the first digit, though. Therefore, we can utilize digits 1 through 9. This is because the number won't be seven digits if there is a zero there. It will change into a number with six digits or fewer. Therefore, by multiplying the number of possible numbers at each digit's place, one can get the number of seven-digit numbers that are feasible.
This gives us the total amount of seven-digit numbers. = 9 cross times 10 cross times 10 cross times 10 cross times 10 cross times 10 cross times 10 equals 9 cross times 10 to the power of 6Half of all 7-digit numbers have the sum of the digits be an odd number, which is rare.
As a result, there are 7-digit numbers with an even sum of digits.
equals 12 cross times 9 cross times 10 to the power of 5 equals 45 cross times 10 to the power of 5 Hence, the correct option is 2
 
Watch 3-min video & get full concept clarity

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon