Mrs. Watters' 4th Review! Angles, decimals, fractions & more...

• They are equal

• Cannot be compared

Answer explanation

To compare \(\frac{3}{4}\) and \(\frac{2}{3}\), convert them to a common denominator or compare their decimal values. \(\frac{3}{4} = 0.75\) and \(\frac{2}{3} \approx 0.67\). Thus, \(\frac{3}{4}\) is greater.

• They are equal

• Cannot be compared

Which of the following numbers is a prime number?

• 9

• 15

• 13

• 21

Answer explanation

A prime number is greater than 1 and has no positive divisors other than 1 and itself. Among the choices, 13 is prime (divisors: 1, 13), while 9 (3x3), 15 (3x5), and 21 (3x7) are not.

If a train leaves at 2:15 PM and arrives at 3:45 PM, how many minutes did the trip take?

• 60 minutes

• 75 minutes

• 90 minutes

• 120 minutes

Answer explanation

The trip starts at 2:15 PM and ends at 3:45 PM. To find the duration, calculate the difference: 3:45 PM - 2:15 PM = 1 hour and 30 minutes, which is 90 minutes. Thus, the correct answer is 90 minutes.

Which angle is an obtuse angle?

• 45°

• 90°

• 120°

• 89°

Answer explanation

An obtuse angle is defined as an angle greater than 90° and less than 180°. Among the options, 120° fits this definition, while 45°, 90°, and 89° are either acute or right angles.

• They are equal

• Cannot be compared

Answer explanation

To compare \(\frac{5}{8}\) and \(\frac{3}{4}\), convert \(\frac{3}{4}\) to eighths: \(\frac{3}{4} = \frac{6}{8}\). Since \(\frac{6}{8} > \frac{5}{8}\), \(\frac{3}{4}\) is greater.

• Cannot be compared

Answer explanation

To compare the numbers, we see that 0.78 is less than 0.87. Therefore, the correct choice is 0.78 < 0.87.

Which of the following numbers is a composite number?

• 7

• 11

• 17

• 18

Answer explanation

A composite number has more than two distinct positive divisors. Among the choices, 18 is composite because it can be divided by 1, 2, 3, 6, 9, and 18. The other numbers (7, 11, 17) are prime.

• 150 mL

• 1,500 mL

• 15,000 mL

• 150,000 mL

Answer explanation

To convert liters to milliliters, multiply by 1,000. Thus, 1.5 liters equals 1.5 x 1,000 = 1,500 mL. Therefore, the correct answer is 1,500 mL.

Which angle is a right angle?

• 60°

• 90°

• 120°

• 45°

Answer explanation

A right angle is defined as an angle that measures exactly 90 degrees. Among the given options, 90° is the only angle that meets this criterion, making it the correct answer.