Jack went to a supermarket with $100 and bought 4 bottles of water. Then his mother called him and asked him to buy twice as many bottles as he already bought. Each bottle cost $2. Finally, he also bought half a pound of cheese and 1 pound of cheese costs $10. How much money does Jack have remaining?
Jack's mother asked him to buy 2 * 4 = 
<gadget id="calculator">2*4</gadget>
<output>8</output>
8 bottles of water.
Thus Jack bought 4 + 8 = 
<gadget id="calculator">4+8</gadget>
<output>12</output>
12 bottles of water in total.
Altogether, the bottles of water cost 12 * $2 = $
<gadget id="calculator">12*2</gadget>
<output>24</output>
24.
The cheese cost 1/2 * $10 = $
<gadget id="calculator">10*0.5</gadget>
<output>5</output>
5.
So Jack spent $24 + $5 = $
<gadget id="calculator">24+5</gadget>
<output>29</output>
29 on water and cheese.
Since he started with $100, he now has $100 - $29 = $
<gadget id="calculator">100-29</gadget>
<output>71</output>
71 left.

<result>71</result>