Element X is a radioactive isotope such that every 70 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 610 grams, how much of
the element would remain after 17 years, to the nearest whole number?

The height of a flare fired from the deck of a ship in distress can be modeled by h(t)= -2(8t^2-52t-28), where h is the height of the flare above water and t is the time in seconds. a. find the time it takes the flare to hit the water.

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?