7th Grade Math Review Quiz

Answer explanation

To find the value of -7 + 12, add 12 to -7. This results in -7 + 12 = 5. Therefore, the correct answer is 5.

Which of the following is a proportional relationship?

Answer explanation

The first choice shows a consistent ratio of cost to apples: $2/3, $4/6, and $6/9 all simplify to 2/3, indicating a proportional relationship. The other options do not maintain a consistent ratio.

Answer explanation

To solve for x in the equation x - 8 = -3, add 8 to both sides: x = -3 + 8, which simplifies to x = 5. Thus, the correct answer is x = 5.

Answer explanation

The area of a rectangle is calculated by multiplying its length by its width. Here, area = 8 cm * 3 cm = 24 cm². Therefore, the correct answer is 24 cm².

Which of the following probabilities represents an event that is certain to happen?

Answer explanation

The probability of 1 represents an event that is certain to happen. In probability, 0 indicates impossibility, while values between 0 and 1 indicate varying degrees of likelihood. Therefore, the correct answer is 1.

Answer explanation

To calculate -3.5 + 2.8, combine the numbers: -3.5 + 2.8 = -0.7. Thus, the correct answer is -0.7.

Answer explanation

To find the amount of water needed for 15 cups of rice, set up a ratio: 4 cups of water for 5 cups of rice. For 15 cups, calculate (15/5) * 4 = 3 * 4 = 12 cups of water. Thus, the correct answer is 12.

Answer explanation

To solve for x in the equation 2x + 5 = 17, subtract 5 from both sides to get 2x = 12. Then, divide both sides by 2 to find x = 6. Thus, the correct answer is x = 6.

Answer explanation

The volume of a right prism is calculated using the formula: Volume = Base Area × Height. Here, Volume = 10 cm² × 7 cm = 70 cm³. Therefore, the correct answer is 70 cm³.

Which of the following events is most likely to occur?

• Drawing a red card from a standard deck of cards

• Flipping a coin and getting heads

Answer explanation

Flipping a coin and getting heads has a probability of 1/2, while rolling a 7 on a 6-sided die (impossible), drawing a red card (1/2), and drawing a joker (impossible) are less likely or impossible events.