Question

10. The number of numbers lying between 10 and 1000 can be formed with the digits 2,3,4,0,8,9
is
(a) 124
(b) 120 c) 125 (d) none of these
​

Answer 1

Answer:

C) 125

Step-by-step explanation:

Case 1: two digit numbers:

Choose the first digit 5 ways (can't choose 0)

Choose the second digit 5 ways (can choose 0)

That's 5*5 = 25 two digit numbers.

Case 2: three digit numbers

Choose the first digit 5 ways (can't choose 0)

Choose the second digit 5 ways (can choose 0)

Choose the third digit 4 ways.

That's 5*5*4 = 100 three-digit numbers.

Grand total: 25+100 = 125

Answer 2

Answer:

C) 125

Step-by-step explanation:

Case 1: two digit numbers:

Choose the first digit 5 ways (can't choose 0)

Choose the second digit 5 ways (can choose 0)

That's 5*5 = 25 two digit numbers.

Case 2: three digit numbers

Choose the first digit 5 ways (can't choose 0)

Choose the second digit 5 ways (can choose 0)

Choose the third digit 4 ways.

That's 5*5*4 = 100 three-digit numbers.

Grand total: 25+100 = 125