The function h is defined by h(x)=(20x−k)÷x+50, where k is a constant. find k, if the value of ℎ at x=20 is equal to 65. anyone who gets this right gets 50 i mean it oh and brainliest

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?

Three coins are flipped. what is the probability that there will be at least two tails?

On saturday morning, calls arrive at ticketmaster at a rate of 108 calls per hour. what is the probability of fewer than three calls in a randomly chosen minute?