1. A piece of equipment consumes c cents per hour of fuel and requires d dollars per hour for other operational costs. What is the cost in dollars of operating the equipment for 500  hours?   5 c + 500 d   500 c + 5 d   5 (c + d)   0.01 c + d   500 (c + d)   Hint Half-n-half Clue   2. The arithmetic mean of 10, 13, and n is 21. What is the value of n?   cannot be determined   21   23   44   40   Half-n-half Clue   3. There are 560  animals on a farm. Three-fourths of them are cows. Of the cows, about 90% are white. How many cows on the farm are not white?   140   378   55   420   41   Half-n-half Clue   4. If a / b = - 4 / 5, then b3 / a3 is equal to   - 64 / 125   64 / 125   125 / 64   25 / 16   - 125 / 64   Half-n-half Clue