Kitty bought 20 books at a book fair. The mean cost of 15 of the books was $12. The total cost of the other 5 books was $40. Find the mean cost of the 20 books

The length of the line segment joining the midpoints of sides ab and bc of the parallelogram abcd is 10. find the length of diagnol ac

Circle a has a diameter of 7 inches, a circumference of 21.98 inches, and an area of 38.465 square inches. the diameter of circle b is 6 inches, the circumference is 18.84 inches, and the area is 28.26 square inches. part a: using the formula for circumference, solve for the value of pi for each circle. (4 points) part b: use the formula for area and solve for the value of pi for each circle. (4 points)

Is triangle jkl congruent to triangle rst? if so, what is the scale factor?