Question

In the integer 2,478 the digits are all different and they increase from left to right. How many integers between 2,000 and 3,000 have digits that are all different and increase from left to right?

Answer 1

agh no answers ?

Answer 2

Wait I am thinking.

Answer 3

A 14
B 35
C 210
D 5
E 123

Answer 4

We've a choice of the last 3 digits. (2 is fixed)
_ _ _
The first digit has to be 3-9. 7 choices
The second digit has to be 4-9. 6 choices
The third digit has to be 5-9. 5 choices.
So, total no. of integers possible=7X6X5=210.

Answer 5

Great! thanks!