Which of the following is not true about function. a) We present a function as a mapping diagram
b) A function machine can have multiple inputs
c) Input in a function is a must, but the output is optional
d) it is a relationship between two sets of numbers

Aswimming pool has an input pump for filling the pool and an output pump for emptying the pool. the input pump can fill the pool in 3 hours, and the output pump can drain the pool in 5 hours. as you go to bed, the pool is full, but a neighbor’s kid turns on the output pump. at midnight, you awake to find the pool half empty. immediately, you turn on the input pump, but you are sleepy and forget to turn off the output pump. at what time will the pool become full?

Which expression is a perfect cube? a. x8 b. y24 c. m28 d. x64

Is the response to the survey question "did you smoke in the last week question mark "response to the survey question "did you smoke in the last week? " a discrete random variable, a continuous random variable, or not a random variable?