Q: John buys 2 packs of gum and 3 candy bars. Each stick of gum cost half as much as the candy bar. If the candy bar cost $1.5 each, how much did he pay in total?
A: The gum cost $1.5 / 2 = $.75 per pack. So he pays $.75 * 2 = $1.5 for the gum. He pays $1.5 * 3 = $4.5 for the candy bars. So in total, he pays $1.5 + $4.5 = $6. The answer is 6.

Q: Mr. Grey is purchasing gifts for his family. So far he has purchased 3 polo shirts for $26 each; 2 necklaces for $83 each; and 1 computer game for $90. Since Mr. Grey purchased all those using his credit card, he received a $12 rebate. What is the total cost of the gifts after the rebate?
A: Mr. Grey paid $26 / shirt x 3 shirts = $78 on polo shirts. He paid $83 / necklace x 2 necklaces = $166 on necklaces. So, he paid $78 + $166 + $90 = $334 for the gifts. After the rebate, the total cost of the gifts is now $334 - $12 = $322. The answer is 322.

Q: The seats of a bus are arranged in 23 rows of 4 seats. At the start, 16 people climb. At the first stop, 15 people board the bus and 3 get off. At the second stop, 17 people get on the bus and 10 get off. How many empty seats are there after the second stop?
A:
There are 23 * 4 = 92 seats on this bus. After the first stop, there are 16 + 15 - 3 = 28 people on the bus. After the 2nd stop, there are 28 + 17 - 10 = 35 people on the bus. So there are 92 - 35 = 57 empty seats on the bus after the 2nd stop. The answer is 57.