The oldest child in a family of four children is twice as old as the yougest. The two middle children are 13 and 16 years old. If the average age of the children is 13.25 , how old is the youngest child? Your answer is :

Thales was an ancient philosopher familiar with similar triangles. one story about him says that he found the height of a pyramid by measuring its shadow and his own shadow at the same time. if the person is 5-ft tall, what is the height of the pyramid in the drawing?

Asurvey of 2,000 doctors showed that an average of 3 out of 5 doctors use brand x aspirin. how many doctors use brand x aspirin

Which value of y will make the inequality y< -1 false?