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4 years ago

14

There are 18 animals. Some cows and some ducks with a total of 60 legs. How many cows and how many ducks?

1 answer:

malfutka [58]4 years ago

5 0

X + Y = 18
X=chickens, Y=Cows
2x + 4y = 60
Let's try 8 and 10.
16 + 40=56, no, 32+20=52, no. 8&10 do not work.
Let's try 9 and 9.
18+36=54, no. 9&9 do not work.
Let's try 11 & 7.
22+28=50, no. 14+44=58, no.
Let's try 12 & 6.
24+24=48, no. 12+48=60 YES!
There are 12 cows and 6 chickens.

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The reference angle is $\frac{\pi}{3}$

Step-by-step explanation:

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The reference angle is the acute angle, that a given angle makes with the x-axis.

First let us make a sketch of the given angle. <em>See diagram in attachment.</em>

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