ISEE Middle Level Quantitative : Numbers and Operations

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

varsity tutors app store varsity tutors android store

Example Questions

Example Question #261 : Numbers And Operations

 is % of what number?

Round to the nearest thousandth.

Possible Answers:

Correct answer:

Explanation:

Remember that for percentages, the key to setting up the problem is intelligent translation. The word "is" becomes , "of" signals multiplication, "what" (and equivalent words) signal a variable ().

Therefore, we can translate:

 is % of what number?

As...

To solve, divide both sides by :

Rounded, this is:

Example Question #41 : Percentage

500 is  of what number?

Possible Answers:

Correct answer:

Explanation:

 of a number is equal to

 

of the number.

The question becomes equivalent to asking this - 500 is  of what number? 

We can find out by dividing 500 by :

.

Example Question #41 : Percentage

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

Jack scores a 40 on his first test and improves his score by 80% on his second test. Jill scores 50 on her first test, and her second test is 130% of her first test.

Column A          Column B     

Jack's 2nd         Jill's 2nd

test score          test score

Possible Answers:

The two quantities are equal.

The quantity in Column A is greater.

The quantity in Column B is greater.

The relationship cannot be determined from the information given.

Correct answer:

The quantity in Column A is greater.

Explanation:

Jack improves by 80%, so we multiply his original score by 1.8 (the 1 to represent his earlier score and the .8 to add on his improvement). 40% times 1.8 equals 72%.

Jill's second test is 130% of her first test (that is, a 30% improvement). To find her new score we multiply her first score by 1.3. 50% times 1.3 equals 65%.

Thus, Jack's second test score is higher.

Example Question #263 : Numbers And Operations

 of 2,001 is 1

 of 1,999 is 1

Which is the greater quantity?

(a) 

(b) 

Possible Answers:

(b) is greater

(a) is greater

(a) and (b) are equal

It is impossible to tell from the information given

Correct answer:

(b) is greater

Explanation:

No calculation is necessary. The whole in (b) is less, so 1 is a greater portion of that whole than the whole in (a). This makes (b) greater.

Example Question #42 : Percentage

Which is the greater quantity?

(a) 

(b) 

Possible Answers:

(a) and (b) are equal

It is impossible to tell from the information given

(a) is greater

(b) is greater

Correct answer:

(a) is greater

Explanation:

 can be rewritten as 

Example Question #43 : Percentage

1,111 is  of 999

999 is  of 1,111

Which is the greater quantity?

(a) 

(b) 

Possible Answers:

(a) is greater

(b) is greater

(a) and (b) are equal

It is impossible to tell from the information given

Correct answer:

(a) is greater

Explanation:

No calculation is necessary. In (a), the part is greater than the whole, so the percent  must be greater than 100. In (b) The part is less than the whole, so  must be less than 100. Therefore, 

Example Question #44 : Percentage

There were 48 pieces of fruit brought to the brunch. Twelve of the pieces of fruit were bananas. What percentage of the fruit were bananas?

Possible Answers:

50%

12%

66%

48%

25%

Correct answer:

25%

Explanation:

Percentage involves part over whole. The total number of fruit was 48. The number of bananas was 12. Therefore, you can make a fraction from those numbers: . Then, to find the percentage, divide 12 by 48. This gives you 0.25. To find the percentage, move the decimal point to the right two places. This gives you 25%.

Example Question #6 : How To Find Percentage

70% of 4,000 is equal to what percent of 6,400?

Possible Answers:

Correct answer:

Explanation:

70% of 4,000 is equal to , which is 

 percent of 6,400.

Evaluate:

The correct response is 

Example Question #7 : How To Find Percentage

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

(A) 70% of 40% of 

(B) 40% of 70% of 

Possible Answers:

(A) and (B) are equal

(A) is greater

(B) is greater

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

Correct answer:

(A) and (B) are equal

Explanation:

40% of a number is the number multplied by 0.40; 70% of the number is the number multiplied by 0.70.

40% of  is ; 70% of that is 

70% of  is ; 40% of that is 

Regardless of the value of , the quantities are equal.

Example Question #3 : How To Find Percentage

 is a positive integer. Which is the greater quantity?

(A) 25% of 

(B) 50% of 

Possible Answers:

(B) is greater

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

(A) and (B) are equal

(A) is greater

Correct answer:

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

Explanation:

The greater of the two can be shown to depend on the value of .

 

Example 1: 

Then 25% of  is equal to 

and 50% of  is equal to 

This makes (A) greater.

 

Example 2: 

Then 25% of  is equal to 

and 50% of  is equal to 

This makes (B) greater.

 

Therefore, insufficient information is given in the problem to determine which is the greater.

Learning Tools by Varsity Tutors