Question 1

It is sunny on 83% of the 120 days Silver Slides Waterpark is open on average. How many days will Silver Slides be open this summer?

Accepted Answer

100. 83% is equal to approximately 5/6. 5/6 times 120 is equal to 100.
Key Takeaway: Covert tricky percentages into fractions that are easy to work with.

Question 2

What is the mean for the following expenditures? $79.84, $278.99, $342.16, $466.25, $111.39, $502.47, $98.12

Accepted Answer

The mean for the data set above is $268.46. The median or middle number when the numbers are in ascending order ($79.84, $98.12, $111.39, $278.99, $342.16, $466.25, $502.47) is $278.99.

Question 3

Which of the following uses the doubling method of informal counting to solve the following:3+4=

Accepted Answer

The doubling method would be 3 + 4 = (3 + 3) +1 = 6 + 1 = 7. Using the doubling method of informal counting involves taking apart a number so that it is the same number as the one being added to it and then adding the difference. It is a way to do mental math easily in one's head.

Question 4

Which type of chart or graph would be the best graphic organizer to demonstrate the relationship between foreign aid to a nation and the decrease in child mortality rates among its citizens?

Accepted Answer

Line graphs are the best graphic organizer to demonstrate a relationship between two factors over a period of time, such as the effect of foreign aid on the child mortality rate of an impoverished nation. Histograms are best suited for displaying the distribution of probability. Pie charts are best for displaying how a whole unit is divided into parts. Bar graphs are best for displaying discrete information in a comparative manner.

Question 5

What kind of triangle has 1 angle that is 90°?

Accepted Answer

A triangle that has 1 angle that is 90° is a right triangle. A right triangle has 1 right angle.

Question 6

Seven/Twelve has $4 million in sales over the past week. What were the approximate sales per day?

Accepted Answer

$571,000. $4 million divided by 7 days is an average of $571,429 per day.
Key Takeaway: Dividing by seven is an important skill because of the week unit is frequently used. If you remembered the repeating decimal we gave you earlier, all you have to do is move it over in this question.
1/7 = .142857
2/7 = .285714
3/7 = .428571
4/7 = .571428
5/7 = .714285
6/7 = .857142

Question 7

What is 1 ½ as a simple fraction in lowest terms?

Accepted Answer

1 ½ as a simple fraction in lowest terms is 3/2. 1 ½ is a mixed fraction. To simplify it, you multiply the denominator (2) by the whole number (1) and then add the product (2) to the numerator (1): 2 x 1 = 2, then 2 + 1 = 3. Put your answer over the denominator (2). The answer is 3/2.

Question 8

Identify the pattern in the following set of numbers:2, 5, 8, 11, 14, 17

Accepted Answer

The pattern is that the set starts with 2 and jumps 3 each time.

Question 9

What is 2/9?

Accepted Answer

2/9 is .22222… The 2s repeat forever.
Key Takeaway: The 9s are easy if you know the trick.
1/9 = .11111…
2/9 = .22222
3/9 = 1/3 = .333333
And so on.

Question 10

What is 3/8s?

Accepted Answer

3/8 is .375.
Key Takeaway: 1/8 is equal to .125.
0.125 is a pretty easy number to work with. Just multiply by your numerator. So 7/8 is .125 times 7, or .875. Dividing by 8 is pretty common, so we recommend you save yourself precious seconds by remembering this.

Question 11

94% of Jim's income last year came from his salary. The rest came from awards his prize winning poodle won in dog shows. If he won $9,600 in dog shows, what was his total income?

Accepted Answer

$160,000.
In this case, 94% is a pretty lousy number to work with. 6% is much better.
If 6% equals $9,600, then 1% = $1,600. Thus, 100% is equal to $160,000.
Key Takeaway: This question is all about speed. By finding easy numbers to work with, you can do this question in a flash.

Question 12

What is the perimeter of a rectangle that has 2 sides measuring 4 cm and 2sides measuring 6 cm?

Accepted Answer

A rectangle that has 2sides measuring 4 cm and 2sides measuring 6 cm has a perimeter of 20. To get this answer, you add the sum of all sides: 4+4+6+6=20.

Question 13

According to the US Standard system, which of the following would be used to measure the volume of water in a bath tub?

Accepted Answer

According to the US Standard system, gallons would be used to measure the volume of water in a bath tub. Other countries do not use gallons as a way of measurement. A US Standard liquid gallon is approximately 4.5 liters.

Question 14

The wholesale price of a fountain pen is $2.80. What will the new price be if a 5% increase is instituted?

Accepted Answer

$2.94. To find 5% of a number, first find 10%, then halve it. In this case, 10% of $2.80 is $0.28. Half of that is $0.14. Add the 14 cents to $2.80 to get $2.94.
Key Takeaway: Logical reasoning is critical with percent problems. Knowing how to manipulate numbers in relation to "friendly" numbers is important. For example, to find 5%, halve 10%. To find 20%, double 10%.

Question 15

Kathleen projects her expenditures for purchasing office supplies to be $85/week. How much will she spend on office supplies over a 4-week time span?

Accepted Answer

$340. It is very easy to mentally multiply a number by 4. Simply double the number, then double that resulting number. In this case, 85 doubled is 170, and 170 doubled is 340.
Key Takeaway: This trick of doubling numbers twice in order to multiply by four comes in handy when you are doing calculations related to quarters, for example. This isn't a tough question, but speed is what matters here.

Question 16

Jacqueline and Lee are meeting for the weekend somewhere between their cities, which are 420 miles apart. Jacqueline drives 80 mph for the duration of her trip. If they both left home at 10 a.m. and met at 1 p.m., what speed did Lee drive to reach their meeting spot?

Accepted Answer

Lee drove 180 miles at 60 mph to reach the meeting place where Jacqueline arrived after driving 240 miles at 80 mph. Jacqueline drove 80 mph for three hours, which is 240 miles altogether. If she drove 240 miles, then Lee drove what remained of their 420-mile distance, which is 180 miles. She had three hours to complete that distance which means she traveled 60 miles each hour.

Question 17

A business has decided to resurface a floor section in their warehouse. The section is a square that measures 15 feet on one side. How much is the area that needs to be resurfaced?

Accepted Answer

15 x 15 is 225 square feet.
Key Takeaway: To square any number that ends in 5, use this trick.
Take the first digit of the number, in this case 1. Multiply that by itself and the next consecutive digit, which is 2.
So far, we have 1 x (1+1) = 1 x 2 = 2. Then, simply put 25 on the end, which results in 225. This trick works for squaring any number that ends in 5.

Question 18

What is 1/7?

Accepted Answer

Key Takeaway: If you memorize the sequence 1-4-2-8-5-7 you can calculate any number divided by 7 quickly.
1/7 = .142857
2/7 = .285714
3/7 = .428571
4/7 = .571428
5/7 = .714285
6/7 = .857142
Editor's Note: In one of my case interviews, I was asked to calculate how many $70 devices I would need to reach $2 million in revenue. Since someone had taught me this trick, I dispensed with estimating, and told the interview the answer was 28,571.428571. I got the job.

Question 19

Greg's Golf Shop hires teenagers to collect lost golf balls from the city's golf courses. The golf balls are then packaged in boxes of a dozen for reselling. This summer, the workers collected 2,244 golf balls. After repackaging, how many golf balls will be left over?

Accepted Answer

They will all fit into the boxes, with no leftovers. This problem is asking you whether 2,244 is divisible by 12. It is, because 2,244 is divisible by both 3 and 4 (which is how you tell if a number is divisible by 12).
Key Takeaway: There are quick ways to tell if a large number is divisible by smaller ones.
A number is divisible by 2 if its last digit is even.
A number is divisible by 3 if, when you add all 3 digits together, that sum is divisible by 3.
(In the answer above, adding 2+2+4+4 = 12; 12 is divisible by 3, so 2,244 is as well.)
A number is divisible by 4 if the last 2 digits of the number is divisible by 4.
(In the answer above, 44 is divisible by 4, so 2,244 is divisible by 4.)
A number is divisible by 5 if the last digit is 5 or 0.
A number is divisible by 6 if it is even, and divisible by 3.
To determine if a number is divisible by 7, take the last digit, double it, then subtract it from the rest of the number. If the resulting number is divisible by 7, the original number is. For example, consider 132.
Take the last digit (2), double it (4), then subtract that from the rest of the number (13). 13-4 is 9. Nine is not divisible by 7, so 132 isn't either.
A number is divisible by 8 if the number formed by its last 3 digits is divisible by 8.
A number is divisible by 9 if, when you add the digits together, that sum is divisible by 9.

Question 20

Round 6148.11385 to the nearest thousandths place. What is the answer?

Accepted Answer

If you round 6148.11385 to the nearest thousandths place, the answer is 6148.114. In the given number, the 3 is in the thousandths place. The next number used to round it is an 8, which is greater than 5, so you would round the 3 up to 4.

Quiz 1: Math and History: the Story of Jeannette Rankin