Home
Class 12
MATHS
How many 3-digit numbers can be formed f...

How many 3-digit numbers can be formed from the digits 1, 2, 3, 4 and 5 assuming that
repetition of the digits is allowed ?

A

15

B

13

C

12

D

11

Text Solution

Verified by Experts

The correct Answer is:
D
As `0 lt x lt 1`, we have `p lt q`
The number of rational numbers=5+4+3+2+1=15
When p,q have a common factor, we get some rational numbers which are not different from those already counted.
There are 4 such numbers `(2)/(4),(2)/(6),(3)/(6),(4)/(6)`.
`therefore` The required of rational numbers=15-4=11
Promotional Banner

Similar Questions

Explore conceptually related problems

How many 3-digit numbers can be formed from the digits 1, 2, 3, 4 and 5 assuming that repetition of the digits is not allowed ?

How many 3 digit even numbers can be formed from the digits 1, 2 , 3, 4, 5 and 6 assuming that repetition of the digits is allowed .

How many 3 digit odd numbers can be formed by using the digits 1, 2, 3, 4, 5, 6 when the repetition of the digits is not allowed ?

How many 3 digit even numbers can be formed from the digits 1, 2, 3, 4, 5, 6 if the digits can be repeated .

How many 2 digit even numbers can be formed from the digits 1, 2, 3, 4, 5 if the digits can be repeated?

Find the sum of all five digit numbers ,that can be formed using the digits 1, 2, 3, 4 and 5 (repetition of digits not allowed)

How many 3 - digit numbers can be formed by using the digits 1 to 9 if no digit is repeated ?

How many numbers lying between 100 and 1000 can be formed with the digits 0, 1, 2, 3, 4, 5, if the repetition of the digits is not allowed?