Đề thi Olympic Tiếng Anh lớp 9 vòng 30 năm 2013 - 2014

Suppose the operation ▲ is defined as a ▲ b = a2b. If 3 ▲ b = 15, what is the value of b?

Lauren has 4 more than half the number of CDs that her sister has. If her sister has x CDs, which expression represents the number of CDs Lauren has?

The graph above shows the height of a projectile as a function of time. Which is the best estimate of the number of seconds for which the projectile was at least 50 meters high?

The graph above illustrates the relationship between the number of a certain item sold and profit for that item. Which value represents the number of items that need to be sold in order for the company to break even on this item?

The outside edge of a picture frame is x in. long and y in. wide. If the distance from the outside edge to the inside edge of the frame is 4 in., which expression describes the shaded area?

The Corporate Average Fuel Economy (CAFE) for a company's automobiles is the median gas mileage for all of its car models. One company offers eight models with mileage ratings of 14, 34, 21, 27, 38, 16, 22, and 27. What is this company's median gas mileage?

Some children are playing a game with a set of 48 cards numbered 1 through 12 in each of four colors: red, blue, green, and orange. What is the probability of drawing a card numbered 10 or greater from the full set of cards?

In a probability experiment, a set of five quarters was tossed 90 times. For each toss, the number of quarters that landed with heads facing up was counted and recorded. The results are shown in the chart above. According to the data shown in the chart, what is the approximate experimental probability that four or more quarters will land heads up?

If x – y ＞ x + y, which of the following must be true?

Suppose AB is rotated in space around BC so that ∠ABC is always 45°. What solid figure is outlined by the path of the rotating line segment?