[Question]: There are 4 more Muscovy ducks than Cayugas, and 3 more than twice as many Cayugas as Khaki Campbells. If there are 90 ducks total, how many Muscovies are there?
[Answer]: Let x represent the number of Khaki Campbell ducks. Cayugas:3 + 2x. Muscovies:4 + (3 + 2x) = 7 + 2x. Total: x + 3 + 2x + 7 + 2x = 90. 5x + 10 = 90. 5x = 80. x = 16. Muscovy: 7 + 2(16) = 39.
So the answer is 39.

[Question]: Trey has 7 times as many turtles as Kris. Kris has 1/4 as many turtles as Kristen has. How many more turtles does Trey have than Kristen, if Kristen has 12?
[Answer]: Kris has 12 / 4 = 3 turtles. Trey has 3 * 7 = 21 turtles. Trey has 21 - 12 = 9 more turtles than Kristen.
So the answer is 9.

[Question]: Stephen has 110 ants in his ant farm. Half of the ants are worker ants, 20 percent of the worker ants are male. How many female worker ants are there?
[Answer]:
Worker ants:110 / 2 = 55 ants. Male worker ants:55(.20) = 11. Female worker ants:55 - 11 = 44 ants.
So the answer is 44.