Question

the number of integers N between 100 and 1000 such that the sum of the digits in N is 10 is​

Answer 1

Answer is 100

You can solve this sum logically or by permutation and combination

logically ,

between 100 and 101 there will only one possibility and same way for all others

thus,

b/w 100 and 200 there will 10 possibility

Therefore ,

10×10=100