Q: A lumberjack is chopping down trees so he can sell firewood. Each tree he chops produces 4 logs each, and each log is then chopped into 5 pieces of firewood. If the lumberjack has chopped 500 pieces of firewood, how many trees did he chop down?
A: The firewood is made from 500 pieces of firewood / 5 pieces of firewood per log = 100 logs. So the logs are chopped from 100 logs / 4 logs per tree = 25 trees. The answer is 25.

Q: Bob has planted corn in his garden, and it has just started to sprout. A week after planting it, it had grown 2 inches. The next week, its height increased by twice as much as it had the first week. In the third week, it grew 4 times as much as it did the week before. How tall are the corn plants now?
A: The second week it grew twice as much as the first week, so 2 * 2 inches = 4 inches. The third week it grew 4 times as much as in the second week, so 4 * 4 inches = 16 inches. In total, it grew 2 inches + 4 inches + 16 inches = 22 inches. The answer is 22.

Q: Henry scored 50 points on his Geography test, 70 on his Math test and 66 on his English test. If his History score is the average of these 3 scores, what was his total score across all 4 subjects?
A:
The sum of his scores across the first 3 subjects is 50 + 70 + 66 = 186. The average score over the 3 subjects which is his History score is = total / 3 = 186 / 3 = 62. Therefore his score across all 4 subjects = 186 + 62 = 248. The answer is 248.