Question

Vong grilled 21 burgers at a block party. He grilled the same number of pounds of turkey burgers as hamburgers. Each turkey burger weighed 1/4 & each hamburger weighed 1/3 pound. How many of each did Vong grill?

Answer 1

$x-number\ of\ hamburgers\\21-x-number\ of\ turkey\ burgers\\\\\frac{1}{4}x=\frac{1}{3}(21-x)\\\\\frac{1}{4}x=7-\frac{1}{3}x\\\\\frac{3}{12}x+\frac{4}{12}x=7\\\\\frac{7}{12}x=7\ \ \ \ \ |\cdot\frac{12}{7}\\\\x=12\\\\21-12=9\\\\Vong\ grilled\ 12\ hamburgers\ and\ 9\ turkey\ burgers$