Question

Maya had $27. She spent all the money on buying 3 burgers for $x each and 2 sandwiches for $y each. If Maya had bought 2 burgers and 1 sandwich, she would have been left with $11.
A student concluded that the price of each burger is $5 and the price of each sandwich is $6. Which statement best justifies whether the student's conclusion is correct or incorrect?

Answer 1

Anything that is close to. 

Because $27- 3*$5 - 2*6 = 0 and $5*2 +1 *$6 = $16, $27-$16 = $11 left over. I can make a system of equations to prove that this is the correct answer.