bob's lawn-mowing service is a profit-maximizing, competitive firm. bob mows lawns for $30 each. his total cost each day is $250, of which $50 is a fixed cost. he mows 5 lawns a day.

Afish fossil is found in a rock. a foot bone and tooth are found in an older layer of the same rock. what can scientists learn from the rock? a) the area changed from land to water. b) the area changed from water to land. c) the area has always been land. d) the area was once an ocean.

Abox contains 40 number tiles numbered 1 to 40. if a tile is drawn at random, what is the probability that the number drawn is a multiple of 3 or 4? find p(multiple of 4 or multiple of 5)

Acheetah ran 75 meters at a speed of 25 meters per second. how long was the cheetah running? 3 seconds 5 seconds 30 seconds 50 seconds