Which function has the largest amplitude?

The -3 out front of that function means |-3| = 3 is the amplitude, which is the largest of the four functions.

In general, the sine function is

y = A*sin(B(x-C)) + D

where |A| is the amplitude. In the first answer choice, A = -3 so |A| = |-3| = 3.

Cosine has the same format since cosine is just a phase shift of sine.

he has 140 chickens because he has 10 times more chickens than ducks and he has 14 ducks so 14*10=140