1. If 9 students sharpen 18 pencils in 2 minutes, how many students will it take to sharpen 18 pencils in 1 minute?
A.) 2
B.) 9
C.) 18
D.) 36

2. If y varies inversely with x, and y = –16 when x = –64, what is the constant of variation?
A.) 16
B.) 64
C.) 100
D.) 1,024

3. The pair of points (3, 8) and (x, 6) are on the graph of an inverse variation. What is the missing value?
A.) 4
B.) 3
C.) -1
D.) 1,

Respuesta :

A) If 9 students sharpen 18 pencils in 2 minutes,Then if the time is halved, it will take twice as many men to sharpen 18 pencils.Hence it will take 18 students to sharpen 18 pencils in one minute B) y & 1/x. Then y = K/x where K is our constant of proportionality.Then K = yx. When x = -64 and y = -16 then K = -64 * -16 = 1024. Option DC) When x = 3 y = 8. So for an inverse variation K as calculated from B = 3 * 8 = 24.Then when K = 24 and y = 6; we have 24 = 6x. Hence x = 4. Option A