Digits 3

[harpazo]

The sum of the digits of a 2-digit number is 10. The tens digit is 4 times the ones digit. Find the number.

Solution:

Let r and s be the two digits.

r + s = 10
r = 4s

Is this the correct set up?

 

[firemath]

Perfect!

 

[harpazo]

Perfect!

This was an easy one. No credit for me.

 

[topsquark]

@harpazo

You've done well with these. My only suggestion is for clarity: actaully say how you are representing the numbers. For example, "ab" (or even better [math]10a + b[/math] ) so the sum of the digits is a + b and switching the digits does (whatever). When I was reading your solutions I had to sit and figure out which was the 10s and 1s digits.

-Dan

 

[harpazo]

@harpazo

You've done well with these. My only suggestion is for clarity: actaully say how you are representing the numbers. For example, "ab" (or even better [math]10a + b[/math] ) so the sum of the digits is a + b and switching the digits does (whatever). When I was reading your solutions I had to sit and figure out which was the 10s and 1s digits.

-Dan

I forgot to clarify the tens and ones units.