Find the sum of the first 10 term of geometric sequence 1,4,16,64

with solutions

If a and b are the measures of two first quadrant angles and sin a = 4/9 and sin b = 2/5 find sin(a+b).

There is a spinner with 14 equal areas, numbered 1 through 14. if the spinner is spun one time, what is the probability that the result is a multiple of 2 or a multiple of 5?

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