Question

3
How many numbers greater than two lakhs
can be made using the digits 0, 4, 5 and 6
where only the digits 4 and 5 may be repeated
and that too only once?
1] 100
2] 150
3] 180
​

Answer 1

Answer:

make me brainleast for the answer

Answer 2

Answer:

The first digit cannot be 0 so there are remaining 5 choices,For 2nd digit including zero and excluding the first digit we have 5 choices. similarly for3 rd digit we have 4 choices and for4 th we have3 ....like this it goes on

Therefore,the final format is

5*5*4*3*2*1= 600

But 2 digits 4 & 5 gets repeated twice, so we have to eliminate the 2 times of them by dividing the answer by 4 (2*2), so we get

600/(2*2) =600/4 = 150

Answer : 2) 150