Question

a two digit nmbr is 3more than 7times the sum of its digits. how many such nmbrs are there?​

Answer 1

Answer:

Let xy represent the 2 digit number

The value of the number xy is:

10x+y…….(1)

The sum of the digits is:

x+y………(2)

Now,according to question,equation 1 is related to equation 2 by the expression:

10x+y=7(x+y)+3

10x+y=7x+7y+3

3x=6y+3

x=2y+1

Now,we find the possible values of x and y:

y=1;x=2*1+1=3

y=2;x=2*2+1=5

y=3;x=2*3+1=7

y=4;x=2*4+1=9

Pls note that y cant be>4,as in that case x will become a 2 digit number but x and y are both single digit number.

So the possible 2 digit numbers are:

31

52

73

94

So there are 4 possible numbers.