Q.

The number of numbers greater than 400000 that can be formed by using the digit 0, 2, 2, 4, 4, 5 is:


see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

90

b

32

c

20

d

None of the above 

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

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

Take Free Test

Detailed Solution

There are 6 digits and the numbers greater than 400000 will have 6 digits. We have to use all 6 digits at a time, the numbers greater than 400000 will have either 4 or 5 at the extreme left position.
1. When 5 is at the extreme left position, the remaining 5 places can be filled with the digits 0,2,2,4,4. This can be done in 5!2!2!=30 ways
2. When 4 occupies the extreme left position, then the remaining 5 places can be filled by 0,2,2,4,5 digits. This can be done in 5!2!=60
So total numbers greater than 400000 are 30+60 = 90
 
Watch 3-min video & get full concept clarity

tricks from toppers of Infinity Learn

score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon