Donna has 4.2 liters of fertilizer. If each pecan tree needs 0.7 liters of fertilizer and Donna uses all the fertilizer, how many pecan trees does Donna have?

Correct Answer: A

Rationale: To find the number of trees, divide the total amount of fertilizer (4.2 liters) by the amount needed for each tree (0.7 liters). 4.2 / 0.7 = 6 trees. Therefore, Donna has 6 pecan trees. Choice A is correct because the calculation is done accurately. Choices B, C, and D are incorrect as they do not reflect the correct calculation based on the given information.

Correct Answer: A

Rationale: To add fractions, you need a common denominator. In this case, the common denominator is 57 * 75 = 4275. So, (47*75 + 65*57) / 4275 = (3525 + 3705) / 4275 = 7230 / 4275. Simplifying this fraction gives 1 23/35. Choice B: 2 1/3 is incorrect as the correct result is not a mixed number. Choice C: 1 2/3 is incorrect as it does not match the simplified result of the expression. Choice D: 1 5/6 is incorrect as it is a different value from the correct result obtained by adding the fractions.

Correct Answer: A

Rationale: To add 12 1/21 and 3 1/3, first add the whole numbers: 12 + 3 = 15. Then, add the fractions: 1/21 + 1/3. To find a common denominator, multiply 21 by 3 to get 63. Convert 1/21 to an equivalent fraction with a denominator of 63 by multiplying the numerator and denominator by 3, resulting in 3/63. Now add 3/63 (equivalent to 1/21) and 21/63 (equivalent to 1/3) to get 24/63. Simplifying 24/63 gives 8/21. Therefore, the sum is 15 8/21. Choices B, C, and D are incorrect because they do not result from the correct addition of the given numbers and fractions.

Correct Answer: A

Rationale: To determine how much board Alan needs to cut off, subtract the length of the table from the length of the board: 7 7/8 - 6 1/2 = 1 3/8. Therefore, Alan needs to cut off 1 3/8 feet from the board. Choice A is correct. Choice B (2) is incorrect because the subtraction result is 1 3/8, not 2. Choice C (7/8) is incorrect as it represents only the fraction part of the answer, not the whole amount. Choice D (3/4) is incorrect as it is a different fraction value than the result of the subtraction.

Correct Answer: A

Rationale: To convert a fraction into a ratio, you express it as a ratio of two numbers separated by a colon. Therefore, 22/91 as a ratio is 22:91. Choice B (1/3) is a different fraction not equivalent to 22/91. Choice C (22/91) is the original fraction and not the ratio form. Choice D is irrelevant to the question.