Information for Students

q Think About the Basic Concept; Be Sure You’re Thinking About the Right Thing. Many of the items on the test just check to see if you know what terms mean and how to perform basic tasks. Be careful, for example, that you don’t compute the radius when you really need the diameter, or confuse slope with intercept.

Now let’s look at a couple of examples. Many test items are easier than they look at first glance. And usually, the computation—the arithmetic

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will be simpler than what you have been doing in math class.

In these examples, we’ll use several of the tips we’ve mentioned—but watch especially how we eliminate choices that are wrong.

# Example 1

# Sample CAHSEE Question

Tina is filling a 45 gallon tub at a rate of 1.5 gallons of water per minute. At this rate, how long will it take to fill the tub?

A 30.0 minutes B 43.5 minutes C 46.5 minutes D 67.5 minutes

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Solution To find the correct answer to this question, you’re supposed to divide 45 by 1.5 to get 30. But imagine that you’re nervous and you can’t decide whether to add, subtract, multiply, or divide.

So think about the situation and use what you know. The tub holds 45 gallons. Tina is putting in 1.5 gallons every minute. How much water is there after one minute? 1.5 gallons. What about ten minutes? That would be 15 gallons (10 times 1.5). So after 20 minutes Tina has 30 gallons, and 30 minutes is 45 gallons.

Let’s look at a different strategy for the same problem. If the water were coming in at 1.0 gallon per minute, it would take 45 minutes to fill. But the water is coming in faster, so it will take less time to fill the tub. Only options A and B are less than 45 minutes. (You just eliminated options C and D!) But option B (43.5 minutes) is only slightly less, while 1.5 gallons per minute is quite a bit more than 1.0. So the correct answer must be option A.

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