Correct Answer: B

Rationale:
Rationale:
1. Let x be the volume of the 10% solution needed and y be the volume of water needed.
2. The total volume of the final solution is 200ml, so x + y = 200.
3. The concentration of the final solution is 5%, so the amount of salt in the final solution is 0.05 * 200 = 10g.
4. The amount of salt in the 10% solution is 0.1x, and the amount of salt in the water is 0, so the total amount of salt in the final solution is 0.1x.
5. Since the total amount of salt in the final solution is 10g, we have 0.1x = 10.
6. Solving for x, we get x = 100ml.
7. Substituting x =

Correct Answer: D

Rationale: When you multiply 2 by 5, the result is 10, not 13.
Therefore, the correct answer is 10, which is option D.

Choices A, B, and C are incorrect because they do not represent the correct product of multiplying 2 by 5.

Correct Answer: D

Rationale:
To make one cake, you need 2½ cups of flour.
To make 6 cakes, you would need 6 times the amount of flour for one cake, which is 2½ x 6 = 15 cups.
Therefore, the correct answer is 15 cups.

Choices A, B, and C are incorrect as they do not correctly calculate the total amount of flour needed for 6 cakes.

Correct Answer: B

Rationale:
Rationale:
- Relatively prime numbers are numbers that share no common factors other than 1.
-
To determine if two numbers are relatively prime, we need to find the greatest common divisor (GC
D) of the two numbers. If the GCD is 1, then the numbers are relatively prime.
- Let's calculate the GCD for each pair of numbers:

A) GCD(12, 16) = 4, not relatively prime

B) GCD(15, 17) = 1, relatively prime

C) GCD(20, 24) = 4, not relatively prime

D) GCD(28, 36) = 4, not relatively prime


Therefore, the pair of numbers 15 and 17 are relatively prime because their greatest common divisor is 1, meaning they share no common factors other than 1.

Correct Answer: A

Rationale:
To convert Celsius to Fahrenheit, you can use the formula: (°C 9/5) + 32 = °F. Substituting 15°C into the formula gives us (15 9/5) + 32 = 59°F.
Therefore, the approximate temperature on the Fahrenheit scale for 15 degrees Celsius is 59 degrees Fahrenheit.
Choice B, C, and D are incorrect as they do not align with the correct conversion formula and calculation.