Explain why n(n-1) must be an even number​

An elevator travels 310 feet in 10 seconds. at that speed, how far can't his elevator travel in 12 seconds?

Someone answer this asap for gabriella uses the current exchange rate to write the function, h(x), where x is the number of u. s. dollars and h(x) is the number of euros, the european union currency. she checks the rate and finds that h(100) = 7.5. which statement best describes what h(100) = 75 signifies? a. gabriella averages 7.5 u. s. dollars for every 100 euros. b. gabriella averages 100 u. s. dollars for every 25 euros. c. gabriella can exchange 75 u. s. dollars for 100 euros. d. gabriella can exchange 100 u. s. dollars for 75 euros.

Atown has a population of 12000 and grows at 3.5% every year. what will be the population after 7 years, to the nearest whole number?