Which statement best classifies air?* 1 point
O Air is a pure substance because it is composed of pure substances.
O Air is a pure substance because its properties rarely change.
OAir is a mixture because it has the same properties at all times.
O Air is a mixture because its composition varies.

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.

Through non-collinear points there is exactly one plane.

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class