Asmall train at an amusement park is carrying passengers. half of the passengers are 6 years old, 1/10 are 7 years old, 1/5 are 8 years old, 1/5 are 9 years old. what is the expected age for 1 of the passengers on the train?

How many days was the temperature above 90 degrees?

The perimeter of a triangle is 69 cm. the first is 5 cm shorter than the second side. the third side is twice as long the first side. find the length of each side

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning