Class 11

Math

Algebra

Permutations and Combinations

A seven digits number with distinct digits is in form of $abcdefg$. ($g,f,e$ etc are digits at units, tens, hundred plane etc.) where $a<b<c<d<e<f<g$. The number of such numbers are:

- $1981$
- $2009$
- $1560$
- $1870$

**Correct Answer: ** Option(c)