If Greg buys 3 shirts, 4 trousers and 2 ties, the total cost is $90. If Greg buys 7 shirts, 2 trousers and 2 ties, the total cost is $50. How much will it cost him to buy 3 trousers, 5 shirts and 2 ties? Choose the correct choice from the following choices:
A) $60  B) $70  C) $75  D) $96  E) Cannot be determined
Solution: 3x+4y+2z=90 7x+2y+2z=50   adding both the equations= 10x+6y+4z=140   5x+3y+2z=70   ans $70
<result>B</result>
If Greg buys 3 shirts, 4 trousers and 2 ties, the total cost is $90. If Greg buys 7 shirts, 2 trousers and 2 ties, the total cost is $50. How much will it cost him to buy 3 trousers, 5 shirts and 2 ties?