ISEE Middle Level Quantitative : Numbers and Operations

Study concepts, example questions & explanations for ISEE Middle Level Quantitative

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Example Questions

Example Question #2 : Whole And Part

 is a multiple of 2, but not a multiple of 6. If  is divided by 6, What could be the remainder?

Possible Answers:

Correct answer:

Explanation:

If the remainder of dividing  by 6 is 0, then  must be a multiple of 6, which contradicts what we are given.

Suppose we call  and  the quotient and remainder, respectively, of dividing  by 6. Then 

If the remainder is 1, then

, as a product of two integers, one even, is an even number; if 1 is added, the result is odd. Therefore, if 1 is the remainder,  is odd, which also contradicts what we are given about . 1 cannot be the remainder, and for similar reasons, neither can 3. 

This leaves 2, which can be the remainder; for example, 8, which is a multiple of 2, but not a multiple of 6, yields a quotient of 1 and a remainder of 2 when divided by 2.

Example Question #221 : Numbers And Operations

Using the information given in each question, compare the quantity in Column A to the quantity in Column B.

Column A                       Column B

120% of 80% of 100       130% of 70% of 105

Possible Answers:

The quantity in Column B is greater.

The quantity in Column A is greater.

The relationship cannot be determined from the information given.

The two quantities are equal.

Correct answer:

The quantity in Column A is greater.

Explanation:

Remember that "percent" means "per 100" and "of" means to multiply.

So 120% of 80% of 100 =

and 130% of 70% of 105 =

Column A is greater.

Example Question #222 : Numbers And Operations

Which is the greater quantity?

(a) 

(b) 

Possible Answers:

It is impossible to tell from the information given

(b) is greater

(a) and (b) are equal

(a) is greater

Correct answer:

(a) is greater

Explanation:

 can be rewritten as , and restated as 

Example Question #223 : Numbers And Operations

What is 60% of 60% of 25,000?

Possible Answers:

Correct answer:

Explanation:

60% of 25,000 is equal to 

60% of that is 

Example Question #224 : Numbers And Operations

 is a positive number. Which of the following is the greater quantity?

(A) 50% of 

(B) 20% of  

Possible Answers:

(A) and (B) are equal

(B) is greater

(A) is greater

It is impossible to determine which is greater from the information given

Correct answer:

(B) is greater

Explanation:

50% of  is equal to .

20% of  is equal to 

Since  is positive and 

,

and (B) is greater.

 

Example Question #225 : Numbers And Operations

What is 42 percent of 5?

Possible Answers:

Correct answer:

Explanation:

The easiest way to find 42 percent of 5 is to first find 42 percent of 10. 

42 percent of 10 can be calculated by multiplying .42 by 10. This results in 4.2. 

Given that 5 is half of 10, it follows that 42 percent of 5 is equal to half of 4.2. 

Half of 4.2 is equal to 2.1, which is the correct answer. 

Example Question #226 : Numbers And Operations

Katie collects trading cards. 15% of her collection are rare cards. If there are a total of 500 cards in Katie's collection, how many of them are rare?

Possible Answers:

Correct answer:

Explanation:

To begin, you can set up a proportion:

When trying to find a percent of a number, convert the percent into a decimal. To do this, divide the percent by 100.

You then multiply 500 by 0.15. Since 500 represents 100% of Katie's cards, multiplying by 0.15 will give you how many cards equal 15% of the total.

The result is your answer.

Example Question #227 : Numbers And Operations

What is 10% of 30% of 100?

Possible Answers:

Correct answer:

Explanation:

This question asks you to find a percentage of a smaller part of 100. You must first figure out what the smaller part of 100 equals. Since percents are based off of 100, 30% of 100 is the number 30. You must then find 10% of this number.

To do this, multiply 30 times 10%. First, divide the percentage by 100.

Multiply the result times 30.

The new result is your answer.

Example Question #7 : Percentage

Amir will be selling 20% of his stamp collection. If he has 60 stamps now, how many will he have after he sells some of his stamps?

Possible Answers:

Correct answer:

Explanation:

If Amir gets rid of 20% of his cards, he will only have 80% of his cards remaining afterwards.

Therefore, we can figure out how many cards Amir will have after selling 20% of his cards by multiplying times 80% since that will be the amount of cards he will have left, compared to the original number.

To do this, first divide the percentage by 100.

Then, multiply the result of this times 60.

The result is your answer.

Example Question #228 : Numbers And Operations

What is 60% of 120?

Possible Answers:

Correct answer:

Explanation:

In order to figure out what 60% of 120 is, multiply 60% by 120. To do this, first divide your percentage by 100.

Then, multiply the result times 120.

The new result is your answer.

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