Q: Mrs. Watson is grading 120 final exams from her American History class. On Monday, she grades 60% of the exams. On Tuesday, she grades 75% of the remaining exams. On Wednesday, how many more exams does she need to grade?
A: On Monday, Mrs. Watson grades 120 x 60% = 72 final exams. At the end of Monday, she has 120 - 72 = 48 exams left to grade. On Tuesday, she grades 48 x 75% = 36 final exams. On Wednesday, she has 48 - 36 = 12 exams left to grade. The answer is 12.

Q: A certain store sells computer accessories and equipment. Due to a fire outbreak in one of the factories, the price of RAM increased by 30%. After two years, the price stabilized and finally fell by 20% from what it has risen. What is the current price of RAM if it was $50 before the fire?
A: After the fire outbreak, the price of RAM got increased by 30 / 100 * 50 = $15. So before stabilization the price was at 50 + 15 = $65. After the stabilization, the price fell by 20% from $65, so it fell by 20 / 100 * 65 = $13. That means the RAM is currently at 65 - 13 = $52. The answer is 52.

Q: The bald eagle can dive at a speed of 100 miles per hour, while the peregrine falcon can dive at a speed of twice that of the bald eagle.  Starting from the same treetop, if it takes the bald eagle 30 seconds to dive to the ground, how long, in seconds, will it take the peregrine falcon to dive the same distance?
A:
Twice the speed of the bald eagle is 100 * 2 = 200 miles per hour. Let "x" be the time in seconds it takes the peregrine falcon to travel to the ground. Thus, based on the ratio of their speeds, the following expression is given: x = 30 * (100 / 200). Thus, x = 15 seconds. The answer is 15.