How many numbers are there between 100 and 500 with the digits 0, 1, 2, 3, 4, 5 if
(i) repetition of digits allowed
(ii) the repetition of digits is not allowed
Answers
Step-by-step explanation:
ANSWER
Digits are 0,1,2,3,4,5
Between 100 and 500
i) Repetition allowed
0,5 can not be at the hundredth place
100 is to be excluded
so the total number of numbers can be formed =6×6×4−1=143
ii) Repetition not allowed
Hundredth place =4
Tenth place =5
Once place =4
Total =4×5×4=80
How many numbers are there between 100 and 500 with the digits 0, 1, 2, 3, 4, 5 if
(i) repetition of digits allowed
(ii) the repetition of digits is not allowed
i) Repetition of digits allowed
The given digits are 0, 1, 2, 3, 4, 5
We have to find numbers between 100 and 500. So the 100’s place can be filled (by the numbers 1, 2, 3, 4) in 4 ways.
The 10’s place can be filled in (using 0, 1, 2, 3, 4, 5) 6 ways
and the unit-place can be filled in (using 0,1, 2, 3, 4, 5) 6 ways
But the number 100 should be excluded
So the number of numbers between 100 and 500 = 4 × 6 × 6 = 144
(ii) the repetition of digits is not allowed
The 100’s place can be filled (by using 1, 2, 3, 4) 10’s in 4 ways
The 10’s place can be filled in (6 – 1) 5 ways and the unit place can be filled in (5 – 1) 4 ways
So the number of 3 digit number 4 × 5 × 4 = 80