Question

12. How many numbers, each less than 400 can be formed with the digits 1, 2, 3, 4, 5, 6 if
repetition of digits is allowed ?
13. How many ſour - digit even numbers with distinct digits can be formed out of the digit
0, 1, 2, 3, 4, 5, 6 ?​

Answer 1

Step-by-step explanation:

Units digit can be either 2 or 4 since we want an even number

When Units digit is 2

Hundredth digit can have 2 choices (4 or 5)

Tenth digit can have 3 choices (since 2 numbers of 5 have been used for units and hundredth digit)

Even Numbers = 2*3 = 6

When Units digit is 4

Hundredth digit can have 1 choices (5 only)

Tenth digit can have 3 choices (since 2 numbers of 5 have been used for units and hundredth digit)

even numbers=1×3=3

total even numbers=6+3=9