demi has 21 baseball cards and 13 football cards she also has 19 hockey cards and 36 basketball cards how many cards does demi have in all?

Acollege is planning to construct a rectangular parking lot on land bordered on one side by a highway. the plan is to use 680 feet of fencing to fence off the other three sides. what dimensions should the lot have if the enclosed area is to be a maximum?

Arunning track in the shape of an oval is shown. the ends of the track form semicircles. a running track is shown. the left and right edges of the track are identical curves. the top and bottom edges of the track are straight lines. the track has width 56 m and length of one straight edge 130 m. what is the perimeter of the inside of the track? (π = 3.14) 260.00 m 347.92 m 372.00 m 435.84 m

Aswimming pool had 2.5 million liters of water in it. some water evaporated, and then the pool only had 22 million liters of water in it. what percent of the water evaporated?