| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.49 |
| Score | 0% | 70% |
If there were a total of 450 raffle tickets sold and you bought 13 tickets, what's the probability that you'll win the raffle?
| 19% | |
| 16% | |
| 7% | |
| 3% |
You have 13 out of the total of 450 raffle tickets sold so you have a (\( \frac{13}{450} \)) x 100 = \( \frac{13 \times 100}{450} \) = \( \frac{1300}{450} \) = 3% chance to win the raffle.
What is the least common multiple of 3 and 7?
| 10 | |
| 9 | |
| 21 | |
| 8 |
The first few multiples of 3 are [3, 6, 9, 12, 15, 18, 21, 24, 27, 30] and the first few multiples of 7 are [7, 14, 21, 28, 35, 42, 49, 56, 63, 70]. The first few multiples they share are [21, 42, 63, 84] making 21 the smallest multiple 3 and 7 have in common.
What is -5z2 + 3z2?
| -2z-4 | |
| -8z-2 | |
| 8z2 | |
| -2z2 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:
-5z2 + 3z2
(-5 + 3)z2
-2z2
The total water usage for a city is 20,000 gallons each day. Of that total, 34% is for personal use and 45% is for industrial use. How many more gallons of water each day is consumed for industrial use over personal use?
| 1,600 | |
| 2,200 | |
| 11,200 | |
| 9,000 |
45% of the water consumption is industrial use and 34% is personal use so (45% - 34%) = 11% more water is used for industrial purposes. 20,000 gallons are consumed daily so industry consumes \( \frac{11}{100} \) x 20,000 gallons = 2,200 gallons.
What is the next number in this sequence: 1, 3, 5, 7, 9, __________ ?
| 11 | |
| 3 | |
| 16 | |
| 14 |
The equation for this sequence is:
an = an-1 + 2
where n is the term's order in the sequence, an is the value of the term, and an-1 is the value of the term before an. This makes the next number:
a6 = a5 + 2
a6 = 9 + 2
a6 = 11