I have 10 liters of orange drink that are two-thirds water and I wish to add it to 15 liters of pineapple drink that is three-fifths water. But as I pour it, I spill one liter of the orange drink. How much water is in the remaining 24 liters?
There are 15 x 3/5 = 
<gadget id="calculator">15*3/5</gadget>
<output>9</output>
9 liters of water from the 15 liters pineapple drink.
After 1 liter of orange drink was spilled, there were 10 - 1 = 
<gadget id="calculator">10-1</gadget>
<output>9</output>
9 liters of orange drink left.
Out of the 9 liters, 9 x 2/3 = 
<gadget id="calculator">9*2/3</gadget>
<output>6</output>
6 liters are water.
Thus, there are a total of 9 + 6 = 
<gadget id="calculator">9+6</gadget>
<output>15</output>
15 liters of water out of the 24 liters.

<result>15</result>