What is mBC?

A.70

B.140

C.28

D.56

What is mBCD
A.168

B.192

C.220

D.82

The number of revolutions of two pulleys is inversely proportional to their diameters. if a 24-inch diameter pulley making 400 revolutions per minute is belted to an 8-inch diameter pulley, find the number of revolutions per minute of the smaller pulley.

Line u passes through points (-52, -18) and (-29, 53). line v passes through points (90, 33) and (19, 56). are line u and line v parallel or perpendicular?

The students in a class were asked how many siblings they have. the data obtained is represented in the dot plot. the number of students who have no siblings is . the number of students who have three or more siblings is .