| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
A machine in a factory has an error rate of 7 parts per 100. The machine normally runs 24 hours a day and produces 10 parts per hour. Yesterday the machine was shut down for 2 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 204.6 | |
| 172.9 | |
| 180.5 | |
| 215.6 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{7}{100} \) x 10 = \( \frac{7 \times 10}{100} \) = \( \frac{70}{100} \) = 0.7 errors per hour
So, in an average hour, the machine will produce 10 - 0.7 = 9.3 error free parts.
The machine ran for 24 - 2 = 22 hours yesterday so you would expect that 22 x 9.3 = 204.6 error free parts were produced yesterday.
If there were a total of 200 raffle tickets sold and you bought 16 tickets, what's the probability that you'll win the raffle?
| 17% | |
| 8% | |
| 5% | |
| 11% |
You have 16 out of the total of 200 raffle tickets sold so you have a (\( \frac{16}{200} \)) x 100 = \( \frac{16 \times 100}{200} \) = \( \frac{1600}{200} \) = 8% chance to win the raffle.
Which of the following is not an integer?
0 |
|
1 |
|
-1 |
|
\({1 \over 2}\) |
An integer is any whole number, including zero. An integer can be either positive or negative. Examples include -77, -1, 0, 55, 119.
Bob loaned Damon $1,500 at an annual interest rate of 4%. If no payments are made, what is the interest owed on this loan at the end of the first year?
| $9 | |
| $28 | |
| $81 | |
| $60 |
The yearly interest charged on this loan is the annual interest rate multiplied by the amount borrowed:
interest = annual interest rate x loan amount
i = (\( \frac{6}{100} \)) x $1,500
i = 0.04 x $1,500
i = $60
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 15% off." If Ezra buys two shirts, each with a regular price of $21, how much will he pay for both shirts?
| $22.05 | |
| $27.30 | |
| $38.85 | |
| $24.15 |
By buying two shirts, Ezra will save $21 x \( \frac{15}{100} \) = \( \frac{$21 x 15}{100} \) = \( \frac{$315}{100} \) = $3.15 on the second shirt.
So, his total cost will be
$21.00 + ($21.00 - $3.15)
$21.00 + $17.85
$38.85