Question

How many 2 digit number are there having their sum of digits as 9 ? Also, write these numbers

Answer 1

Answer:

9 Digits are possible under given criterion..

Step-by-step explanation:

let the two digit number be 10x+y........\1\

Now

Given

x+y=9 ..........\2\

WKT

x∈{1,2,3,4,5,6,7,8,9}

y∈{0,1,2,3,4,5,6,7,8,9}

Now using each set and \1\ and \2\

The numbers are

18,27,36,45,54,63,72,81,90

Hope it helps...