Question

If A be the set of all two digit number such that
the sum of its digits is at most 5. Then number of
element in set A are
a) 5
b) 10
c) 15
d) 20​

Answer 1

The numbers are:
14, 23, 32, 41, 50

So the answer is a) 5

Answer 2

digits can be

10-14 i.e 5 numbers

20-23 ie 4 numbers

30-32 ie. 3 numbers

40 and 41 ie. 2 numbers

and 50 ie. 1 number

so total 15 such numbers are possible