Answer:
49
Step-by-step explanation:
The "abc" be the number between 100 and 299
So, we can say:
0<a<b<c<9 [from the constraints]
c can take values from 3 - 9 inclusive, so that's 7 values
b can take values from 2 - 8, inclusive, so that's 7 values
a can take only 1 value
So the number of possibilities is:
7 * 7 * 1 = 49
Hence, there are 49 integers between 100 and 299 such that the hundreds digit of n is less than the tens digit of n and the tens digit of n is less than the units digit of n
