Question:

The number of natural numbers less than $7,000$ which can be formed by using the digits $0,1,3,7,9$ (repitition of digits allowed) is equal to :

Updated On: June 02, 2025
  • 250
  • 374
  • 372
  • 375
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

Number of numbers = $2 \times 5^3$
Required number = $5^3 + 2 \times 5^3 - 1$
= 374
Was this answer helpful?
20
9

JEE Main Notification

Concepts Used:

Permutations

A permutation is an arrangement of multiple objects in a particular order taken a few or all at a time. The formula for permutation is as follows:

\(^nP_r = \frac{n!}{(n-r)!}\)

 nPr = permutation

 n = total number of objects

 r = number of objects selected

Types of Permutation

  • Permutation of n different things where repeating is not allowed
  • Permutation of n different things where repeating is allowed
  • Permutation of similar kinds or duplicate objects