Together, Thomas, Ping and Lydia earn $144,000 per month. If Thomas earns $12,000 more than Ping and $18,000 more than Lydia, how much does Thomas earn?

Question

I can't figure out the answer from the choices.

I'm getting $50,000 for Thomas. My equation for this is:

(x+12,000) + (x+18,000) + x = $144,000

 

I think there's something wrong with my solution. Correct me if I'm wrong with your best explanation. Thanks!

Answer 1

Hello Kiddo, You're adding when you should be subtracting.

 

If Thomas earns $12,000 more than Ping

T = 12,000 + P

(T - 12,000) = P

 

and He earns $18,000 more than Lydia

T = 18,000 + L

(T - 18,000) = L

 

how much does Thomas earn?

 

T + (T - 12,000) + (T - 18,000) = 144,000

3T - 30,000 = 144,000

3T = 144,000 + 30,000

3T = 174,000

T = 58,000

 

 

Answer 2

(all numbers in thousands)

 

t + p + l = 144

t = p + 12

t = l + 18

 

Re-arrange to put p and l in terms of t.

 

p = t-12

l = t-18

 

Now plug them into eq. 1.

 

t + (t-12) + (t-18) = 144

3t -30 = 144

3t = 174

t = 58

 

So it just looks like you have the signs reversed in your equation.