Q: Keith and Blaine went fishing. Blaine caught 5 fish while Keith caught twice as many as Blaine's. How many fish did they catch together?
A: Keith caught 5 x 2 = 10 fish. Therefore, they caught a total of 5 + 10 = 15 fish. The answer is 15.

Q: Oprah has 3500 cars in her collection. If the average number of cars she gives away per year is 50, how many years will it take to reduce her car collection to 500?
A: If Oprah wants to have 500 cars left, she will have to give away 3500 - 500 = 3000 cars. Since the average number of cars she gives away per year is 50, it will take her 3000 / 50 = 60 years to give away enough cars to have 500 left over. The answer is 60.

Q: The base of a hill located beside a river is 300m above the seabed. If this depth is a quarter of the vertical distance between the riverbed and the peak of the hill, how high is the hill?
A:
300m is a quarter of the distance from the riverbed to the hill's peak so (1 / 4) * distance from riverbed to peak = 300m. Multiplying both sides of the equation by 4 gives the distance from riverbed to peak = 300m * 4 = 1200m. The height of the hill is the difference between the distance from the riverbed to the hill's peak and the distance from the riverbed to the hill's base which is 1200m - 300m = 900m. The answer is 900.