Question

5. How many numbers lie between 300 g
500 in which 4 comes only one time?
(1) 99
(2) 100
(3) 110
(4) 120​

Answer 1

your question is not correct

Answer 2

Totally 99 numbers lie between 300 and 500 in which 4 comes only one time.

Answer - (option 1)

To find:

The numbers lie between 300 and 500 in which 4 comes only one time

Solution:  

(i) The numbers from 300 – 399 :

Here the hundreds place is fixed as it is 3. Tens and hundreds place can vary from 0 to 9 but they cannot have 4 at the same time.

When 4 is coming in the second place = 1 $\times 9 \times$ 1 = 9

When 4 is coming in the third place = 1 $\times 1 \times 9$ = 9

Total = 9 + 9 = 18

(ii) The numbers between 400 – 499:

Here 4 can have only one place since it is already in the hundreds place, it cannot occur in ones and tens place.

There are 19 numbers in the range where 4 occurs in tens and ones place. 100 – 19 = 81

So, the total combinations = 81 + 18 = 99.