you could either multiply straight away or you could simplify right then so that you wouldn't have to it later.
20/5 * 5/2
your answer would be 10 either way
Answer:

Step-by-step explanation:
It is given that triangle AOC intersects a circle with center O, side AO is 10 inches and the diameter of the circle is 12 inches, thus
OC is the radius of the circle and is equal to
.
Now, From ΔAOC, using the Pythagoras theorem, we get

⇒
⇒
⇒
⇒
It is just 5.0 and you move the decimal right six places
The cosine of A is (adjacent side)/(hypotenuse) = 55/73. Do the division, then find the angle whose cosine is that number. The whole thing takes maybe 6 or 7 seconds with your calculator. It's choice-B.
Let x be the time she ran and y be the time she walked
then distance ran = 25x and distance walked = 5y
so 15x + 5y = 42
and x + y = 4
* second equn. by -5:-
-5x - 5y = -20
add this to the first equn:0
10x = 22
x = 2.2
distance she ran = 2.2 * 15 = 33 km