If the points (−2, 5), (0, y) and (5, −16) are collinear, what is the value of y?

Jeremiah has written four letters, one to each of four different people, and he has an addressed envelope for each person. If Jeremiah randomly places each letter in a different one of the four envelopes, what is the probability that two letters are in the correct envelopes and the other two are not? Express your answer as a common fraction.

For how many nonzero values of x does x\(^{2x}\) = 1?

What fraction of 45 is 60% of 50? Express your answer as a common fraction

Sinclair is going to visit her family in New York. She lives 90 miles away in New Jersey. Assuming that there are no traffic delays and she can travel at an average speed of 45 mi/h for the entire trip, at what time should she leave if she needs to meet her family at 4:00 p.m.?

What number must be added to the set {5, 10, 15, 20, 25} to increase the mean by 5?

Connie and her little brother like to play a number game. When Connie says a number, her brother then says the number that is 3 less than half of Connie’s number. If Connie says a number, and her brother gives the correct response, 9, what number did Connie say?

The average age of a group of 12 people is 26 years. If 8 new people are added to the group, the average age of the group increases to 32 years. In years, what is the average age of the 8 new people?

A wheel that makes 10 revolutions per minute takes 18 seconds to travel 15 feet. In feet, what is the diameter of the wheel? Express your answer as a decimal to the nearest tenth.

What is the closest integer to the real number x such that 2\(^x\) =1000?

At a store, a four-pack of 16-oz cans of soup costs $3.20 and a three-pack of 24-oz cans costs $3.60. How many cents are in the absolute difference between the price per ounce of a four-pack and the price per ounce of a three-pack?

The book of Guinness World Records states that Fuatai Solo set a world record in 1980 by climbing a coconut tree 29 feet 6 inches tall in 4.88 seconds. At that rate, how many minutes would it take Fuatai to climb the 1454 feet to the top of the Empire State Building? Express your answer to the nearest whole number.

The line passing through points (1, c) and (−5, 3) is parallel to the line passing through the points (4, 3) and (7, −2). What is the value of c?

There is a \(\dfrac{2}{3}\) chance of rain for each of three days. If the weather on each day is independent of the weather on the other two days, what is the probability that it will rain on none of the three days? Express your answer as a common fraction.

The area of a right triangle is 36 cm2 . If the length of one leg of this triangle is 8 cm, what is the length of the other leg, in centimeters? 

If 45 + \(\sqrt{c}=49\), what is the value of \(c^2-21\)?

What is the mean of \(7\dfrac{1}{2};-3\dfrac{1}{4};-5\dfrac{1}{4};2\)?

Let @x@ be defined for all positive integer values of x as the product of all of the factors of 2x. For example, @7@ = 14 × 7 × 2 × 1 = 196. What is the value of @3@?

If the point (−3, 5) is reflected across the x-axis, what is the sum of the coordinates of the image?

There are some problems in this web page:

First, I think Phan Huy Toan and phanhuytien are brothers or maybe copiers, because they keep asking and answering together. And they copy, write Vietnamese questions and tick for each other too. This is unusual, so I suggest that the moderators should subtract of delete their account forever.

Second, Vietnamese questions are not allowed in this page so don't ask these question here.

That's what I think.