HSPT Quantitative : How to manipulate numbers

Study concepts, example questions & explanations for HSPT Quantitative

varsity tutors app store varsity tutors android store

Example Questions

Example Question #171 : How To Manipulate Numbers

\(\displaystyle 14\) is what percentage of \(\displaystyle 80\)?

Possible Answers:

\(\displaystyle 5.71\%\)

\(\displaystyle 1.12\%\)

\(\displaystyle 17.5\%\)

\(\displaystyle 0.175\%\)

Correct answer:

\(\displaystyle 17.5\%\)

Explanation:

First, divide \(\displaystyle 14\) by \(\displaystyle 80\):

\(\displaystyle 14\div 80=0.175\)

Next, convert to a percentage by multiplying by \(\displaystyle 100\):

\(\displaystyle 0.175\cdot100=17.5\%\)

Example Question #172 : How To Manipulate Numbers

What is \(\displaystyle 45\%\) of \(\displaystyle 16\)?

Possible Answers:

\(\displaystyle 7\)

\(\displaystyle 7.2\)

\(\displaystyle 7.5\)

\(\displaystyle 8\)

Correct answer:

\(\displaystyle 7.2\)

Explanation:

Multiply \(\displaystyle 16\) by \(\displaystyle 45\%\), or \(\displaystyle 0.45\):

\(\displaystyle 16\cdot0.45=7.2\)

Example Question #173 : How To Manipulate Numbers

What number, when divided by the product of \(\displaystyle 16\) and \(\displaystyle 3.5\), equals the square root of \(\displaystyle 9\)?

Possible Answers:

\(\displaystyle 58.5\)

\(\displaystyle 56\)

\(\displaystyle 18\)

\(\displaystyle 168\)

Correct answer:

\(\displaystyle 168\)

Explanation:

Work backwards to solve this problem. First, the product of \(\displaystyle 16\) and \(\displaystyle 3.5\) is \(\displaystyle 118\):

\(\displaystyle 16\cdot3.5=56\)

Next, the square root of \(\displaystyle 9\) is \(\displaystyle 3\):

\(\displaystyle \sqrt{9}=3\)

Now, the question is, "What number, when divided by \(\displaystyle 56\), equals \(\displaystyle 3\)?"  This can also be written as:

\(\displaystyle \frac{x}{56}=3\)

Multiply both sides by \(\displaystyle 56\) to find \(\displaystyle x\):

\(\displaystyle x=56\cdot3=168\)

Example Question #174 : How To Manipulate Numbers

What number added to 15 gives you \dpi{100} \frac{1}{4}\(\displaystyle \dpi{100} \frac{1}{4}\) of 72 ?

 

Possible Answers:

\dpi{100} 3\(\displaystyle \dpi{100} 3\)

\dpi{100} 6\(\displaystyle \dpi{100} 6\)

\dpi{100} 4\(\displaystyle \dpi{100} 4\)

\dpi{100} 12\(\displaystyle \dpi{100} 12\)

Correct answer:

\dpi{100} 3\(\displaystyle \dpi{100} 3\)

Explanation:

Set up an equation using the information provided.

\dpi{100} 15+x=\frac{1}{4}\cdot 72\(\displaystyle \dpi{100} 15+x=\frac{1}{4}\cdot 72\)

\dpi{100} 15+x=18\(\displaystyle \dpi{100} 15+x=18\)

\dpi{100} 15+x-15=18-15\(\displaystyle \dpi{100} 15+x-15=18-15\)

\dpi{100} x=3\(\displaystyle \dpi{100} x=3\)

Example Question #175 : How To Manipulate Numbers

\(\displaystyle 60\) is \(\displaystyle 5\) percent of what number?

Possible Answers:

\(\displaystyle 1500\)

\(\displaystyle 120\)

\(\displaystyle 150\)

\(\displaystyle 1200\)

Correct answer:

\(\displaystyle 1200\)

Explanation:

Set up a proportion, representing the unknown number with \(\displaystyle x\):

\(\displaystyle \frac{60}{x}=\frac{5}{100}\)

Then cross multiply and solve:

\(\displaystyle 6000=5x\)

\(\displaystyle x=\frac{6000}{5}=1200\)

Example Question #176 : How To Manipulate Numbers

What number, when divided by \(\displaystyle 6\), is half the product of \(\displaystyle 13\) and \(\displaystyle 8\)?

Possible Answers:

\(\displaystyle 404\)

\(\displaystyle 298\)

\(\displaystyle 312\)

\(\displaystyle 415\)

Correct answer:

\(\displaystyle 312\)

Explanation:

First find the product of \(\displaystyle 13\) and \(\displaystyle 8\):

\(\displaystyle 13\cdot8=104\)

Then find half the product by dividing by 2:

\(\displaystyle 104\div2=52\)

Now multiply by \(\displaystyle 6\) to reverse the division:

\(\displaystyle 52\cdot6=312\)

Example Question #177 : How To Manipulate Numbers

What is \(\displaystyle 16\) percent of \(\displaystyle 64\)?

Possible Answers:

\(\displaystyle 12.05\)

\(\displaystyle 10.24\)

\(\displaystyle 4\)

\(\displaystyle 25\)

Correct answer:

\(\displaystyle 10.24\)

Explanation:

Multipy \(\displaystyle 64\) by the decimal version of the percentage:

\(\displaystyle 64\times .16=10.24\)

Example Question #178 : How To Manipulate Numbers

What is \(\displaystyle 6\) percent of \(\displaystyle 106\)?

Possible Answers:

\(\displaystyle 7.3\)

\(\displaystyle 7\)

\(\displaystyle 6.\overline{66}\)

\(\displaystyle 6.36\)

Correct answer:

\(\displaystyle 6.36\)

Explanation:

Multiply the number by the decimal version of the percentage:

\(\displaystyle 106\times .06=6.36\)

Example Question #179 : How To Manipulate Numbers

What is \(\displaystyle \frac{3}{4}\) of \(\displaystyle 13\) less than \(\displaystyle 93\)?

Possible Answers:

\(\displaystyle 48\)

\(\displaystyle 55\)

\(\displaystyle 60\)

\(\displaystyle 80\)

Correct answer:

\(\displaystyle 60\)

Explanation:

First, \(\displaystyle 13\) less than \(\displaystyle 93\) is:

\(\displaystyle 93-13=80\)

Next, find \(\displaystyle \frac{3}{4}\) of that value:

\(\displaystyle \frac{80\cdot3}4{}=60\)

Example Question #180 : How To Manipulate Numbers

What number is 2 percent of 3/8 of 72?

Possible Answers:

\(\displaystyle 5.42\)

\(\displaystyle 1.32\)

\(\displaystyle 2.45\)

\(\displaystyle 0.54\)

\(\displaystyle 0.75\)

Correct answer:

\(\displaystyle 0.54\)

Explanation:

First we need to find 3/8 of 72.  To do this, convert 72 into a fraction and multiply.

\(\displaystyle \frac{3}{8}\cdot \frac{72}{1} = \frac{216}{8}= 27\)

To find 2 percent of 27, convert 2 percent into decimal form (0.02) and multiply it by 27.

\(\displaystyle 0.02 \cdot 27 = 0.54\)

Learning Tools by Varsity Tutors