Correct Answer: A

Rationale: To determine the number of cakes needed, calculate the total number of people, which is 70 students + 3 staff = 73 people. Since each cake serves 24 people, divide the total number of people by 24 to get approximately 3.04. You cannot have a fraction of a cake, so round up to the next whole number, which is 4. Therefore, you need 4 cakes to serve the class of 70 students and 3 staff members. Choice B (2) is incorrect because 2 cakes would not be enough to serve 73 people. Choice C (5) is incorrect as it would be an excess of cakes. Choice D (3) is incorrect because 3 cakes would not be sufficient to serve 73 people.

Correct Answer: C

Rationale: 12 - 7 & 4\5 equals 4 & 1\5.

Correct Answer: B

Rationale: The formula for the area of a rectangle is: Area = Length Width. To find the length, divide the area by the width: 225 · 15 = 15 feet. Therefore, the correct answer is 15 feet. Choice A (30 feet) is incorrect because it is the product of the area and the width, not the length. Choice C (25 feet) is incorrect as it does not match the result of dividing the area by the width. Choice D (45 feet) is incorrect as it is not the result of the calculation needed to find the length.

Correct Answer: C

Rationale: In the number 743.25, the tenths place is the first digit to the right of the decimal point, which is 2. Therefore, the correct answer is C. Choice A (3) represents the hundredths place, choice B (4) represents the units place, and choice D (5) represents the hundredths place.

Correct Answer: A

Rationale: When adding fractions with the same denominator, you simply add the numerators while keeping the denominator the same. In this case, 7/21 + 10/21 = 17/21. Therefore, the correct answer is A. Choice B (15/21) is incorrect because it adds the numerators incorrectly. Choice C (9/21) is incorrect as it does not reflect the sum of the fractions provided. Choice D (10/21) is also incorrect as it does not represent the correct sum of the two fractions.