On a certain day, the exchange rate was 60 u. s. dollars for 50 euro. at this rate about how many u. s. dollars were 70 euro worth that day?

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?

What is the first step of an indirect proof of a number that is divisible by two

Nikolas calculated the volume of the prism. his work is shown below.