An inlet pipe can fill a tank in 10 minutes. A drain can empty the tank in 20 minutes. If the tank is empty, and both the pipe and drain are open, how long will it take before the tank overflows?

Beth divided 9 ounces of her granola recipe into 4 equal-sized amounts. she placed the amounts into individual bowls. the fraction 9/4 represents the number of ounces of granola in each bowl. which other number represents the amount of granola beth has in each bowl? (a) 1 1/4 (b) 2 1/4 (c) 1 3/4 (d) 3 3/4 i need !

Acircus act has 3 times as many elephants as acrobats. jorge noticed that all together there were 56 legs in the circus ring. how many elephants were in the show?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.