Correct Answer: A

Rationale: To find the sum of the numbers 34 + 74 + 37, add them together: 34 + 74 + 37 = 145. Therefore, the correct answer is A. Choice B (155) is incorrect as it results from adding 34 + 74 + 37 incorrectly. Choice C (154) is incorrect as it is the result of adding the first two numbers correctly, but missing the addition of the third number. Choice D (135) is incorrect as it is the result of a calculation error, possibly adding the numbers in a different order.

Correct Answer: B

Rationale: Since the landscaping plan is drawn on a 1:50 scale, the real-life dimensions of the deck can be calculated by multiplying the dimensions on the plan by the scale factor. The dimensions given are 12 cm by 10 cm. Multiplying these dimensions by the scale factor of 50 gives us 600 cm by 500 cm, which is equivalent to 6 m by 5 m in real life. Choice A is incorrect as it doesn't consider the scale factor. Choice C and Choice D are incorrect as they are not the result of multiplying the dimensions by the scale factor.

Correct Answer: C

Rationale: Teresa collected 144 baseball cards in 8 months. To find the average number of cards collected per month, we divide the total number of cards by the total months: 144 cards · 8 months = 18 cards per month. Therefore, on average, Teresa has collected 18 baseball cards per month. Choice A (12), Choice B (16), and Choice D (22) are incorrect as they do not match the correct calculation based on the information provided in the question.

Correct Answer: B

Rationale: To find the final concentration, first, calculate the total volume of the solution (2 ml + 8 ml = 10 ml). Then, determine the concentration by dividing the volume of the concentrated medication by the total volume and multiplying by 100%: (2 ml / 10 ml) * 100% = 20%. Therefore, the correct answer is B. Choice A (16.67%) is incorrect as it does not represent the correct calculation. Choices C (25%) and D (50%) are both incorrect as they do not reflect the accurate concentration resulting from the dilution process.

Correct Answer: C

Rationale: To find the surface area of the cylinder, calculate the lateral surface area using the formula 2πrh, where r is the radius (half of the diameter) and h is the height. Substituting the values, we get 2 * π * 1 * 3 = 6π square meters. Since each can covers 10 sq m, divide the total surface area by the coverage area per can: 6π / 10 ≈ 1.9 cans. Since you can't buy a fraction of a can, you would need to round up, so you would need 2 cans to cover the entire exterior surface. Therefore, you would need 2 * 6 = 12 cans in total. Choices A, B, and D are incorrect as they do not consider the correct surface area calculation or the rounding up to the nearest whole number of cans required.