Question

The sum of two digit number and its reverse is equal to 99. how many such two digit numbers are there?

Answer 1

guess,ones =x  nd tens=y
so no will be =10y+x
its reverse=10x+y

then,
         10y+x+10x+y = 99
     or,11y+11x = 99
     or,11(x+y) = 99
     or,x+y =99/11 =9
     or,x=y=9/2=4.5

so,the no is =10*4.5 + 4.5
                   =45 + 4.5 =49.5

so,the ans is 49.5 

Answer 2

Answer:

9

Step-by-step explanation:

Let the number be 'xy', which are not in multiplication.

According to the question:

$10x+y+10y+x = 99$

$11(x+y) = 99$

$x+y=99/11\\x+y=9$

So, numbers whose digits sum up to 9 will satisfy this condition. There are 9 such numbers.

Thus, the answer is 9.