The result of dividing a two-digit number by the number with its digits reversed is 7\4. If sum of the digits is 12, what is the number?

Question

I really need help with this question because it's late and it's due tommorrow.

Answer 1

The number is 84.

Answer 2

You can solve this either by trial and error or by using 2 equations with 2 unknowns.

 

To use trial and error, realize that the answer will give a fraction or ratio that will reduce to 7/4. So, the resulting ratio will be x/x * 7/4. Then you can try various values of x until you recognize an answer that meets the problem description.

 

To use 2 equations and 2 unknowns, realize that you can express the numerator as (a*10) + b, and the denominator as (b*10) + a, where a and b are the two digits in each number. So, ((a*10) + b)/((b*10) + a) = 7/4. The second equation, of course, is: a + b =12.