Some of the problems are in scientific notation, which if you don't know how to do, I will try to explain, when you see for example 1 x 10^3, what it is saying is basically 1 x 10 x 10 x 10 so in that case 1,000, simple trick is to look at what ever number is in the top right, then add that many zeroes. So this is most likely supposed to be a division problem. if you need more help message me.
So the definition of the cosine of an angle of a right triangle is

. You may remember this by SohCahToa (sine is opposite over hypotenuse, cosine is adjacent over hypotenuse, tangent is opposite over adjacent).
Remember, adjacent refers to the side next to the angle in question, and the side can't also be the hypotenuse. The hypotenuse is that longest side and is opposite the right angle.
We have the cosine of 30°. We write
Round to the nearest percent
She will need more than. 4 x 1/2 is 2 which is more than 1/2