Question 14
A 7-digit number $\overline{abcdefg}$ is said to be V-shaped if it has the following properties:
- No two digits among $a,b,c,d,e,f$ and $g$ have the same value;
- $a>b>c>d$;
- $d<e<f<g$.
How many V-shaped 7-digit numbers are there?
- No two digits among $a,b,c,d,e,f$ and $g$ have the same value;
- $a>b>c>d$;
- $d<e<f<g$.
How many V-shaped 7-digit numbers are there?