A bike rental company rents beach bikes. They charge an initial fee plus $1 for each hour the bike is rented. Chad rented a bike for six hours and was charged $10. How much is the initial fee? -I need help figuring this out, maybe the first step?

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?

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

15/16 as a decimal rounded to the nearest hundredth