In a shop, the cost of 4 shirts, 4 pairs of trousers and 2 hats is $560. The cost of 9 shirts, 9 pairs of trousers and 6 hats is $1,290. What is the total cost of 1 shirt, 1 pair of trousers and 1 hat? Choices
A) $50
B) $320
C) $150
D) $100
E) $400
Let x be the price of one shirt, y be the price of one pair of trousers and z be the price of one hat.   4x + 4y + 2z = 560 :   9x + 9y + 6z = 1,290   3x + 3y + 2z = 430 : divide all terms of equation C by 3   x + y = 130 : subtract equation D from equation B   3(x + y) + 2z = 430 : equation D with factored terms.   3*130 + 2z = 430   z = 20 : solve for z   x + y + z = 130 + 20= 
<gadget id="calculator">130 + 20</gadget>
<output>150</output>
$150   correct answer $150
<result>C</result>
In a shop, the cost of 4 shirts, 4 pairs of trousers and 2 hats is $560. The cost of 9 shirts, 9 pairs of trousers and 6 hats is $1,290. What is the total cost of 1 shirt, 1 pair of trousers and 1 hat?