Element X is a radioactive isotope such that every 18 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 500 grams, how long would it be until the mass of the sample reached 210 grams, to the nearest tenth of a year?

And employees salary increase by $4500 which represents a 15% raise what is the employees new salary

Determine the number of outcomes in the event. decide whether the event is a simple event or not. upper a computer is used to select randomly a number between 1 and 9 comma inclusive. event upper b is selecting a number greater than 4. event upper b has nothing outcome(s). is the event a simple event? (yes or no) because event upper b has (fewer than, exactly, more than) one outcome.

Find the exact value of each of the following. in each case, show your work and explain the steps you take to find the value. (a) sin 17π/6 (b) tan 13π/4 (c) sec 11π/3