The temperature in the ice rink must stay below 50° F. This morning the temperature was 68°F. The ice rink runs a cooling device
2 answers:
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Answer:
Step-by-step explanation:
Use the cosine ratio, . Insert the values:
Isolate x. Multiply both sides by x:
Divide both sides by cos 25:
Insert into a calculator:
Round to the nearest hundredth:
Done.
For this case we must simplify the following expression:
We eliminate the parentheses taking into account that:
So:
We add similar terms taking into account that:
Equal signs are added and the same sign is placed.
Different signs are subtracted and the major sign is placed.
Answer:
So, the total number of balls is 11. We want to pick 2 red balls and 1 green ball. WLOG (since order doesnt matter here), we can say he picks red, green, red. That means on his first pick, he has a chance of picking the red ball, and he places it back in the bag. The probability of picking a green ball is
, and then he places the ball back in the bag. The probability of picking the last red ball is the same as the last red ball example, and we simply multiply the probabilities together as per the multiplication rule to get:
Now, without replacement the order does matter. He picks a red ball, a red ball then a green ball. The probability of picking the first red ball is, and the probability of picking the second red ball is
and the probability of picking the green ball is
. We want to multiply thm again, as per the multiplication rule like the last problem.