1. If f(x, y) = 2 y - x2 where x and y are real numbers, then f( f(3, 5), 5) is equal to   -1   9   1   -9   -11   Hint Half-n-half Clue   2. A gas cylinder has two vents, V1 and V2, for discharge. The cylinder empties in 8  minutes when only vent V1 is open. The cylinder empties in 2  minutes when both vent V1 and vent V2 are open. About how many minutes will the cylinder take to empty if only vent V2 is open?   cannot be determined   6.00   2.67   1.60   0.17   Half-n-half Clue   3. A large water reservoir has two outlet pipes, a small one and a large one. It takes 6  hours to empty the reservoir when only the small outlet pipe is open. It takes 3  hours to empty the reservoir when only the large outlet pipe is open. About what fraction of the reservoir will be emptied in one hour if both the pipes are open?   0.50   0.17   0.33   0.17   cannot be determined   Half-n-half Clue   4. If a / b = - 7 / 8, then b3 / a3 is equal to   512 / 343   - 343 / 512   343 / 512   64 / 49   - 512 / 343   Half-n-half Clue