Add 7/8 + 9/10 + 6/5. Express the result as a mixed number.

Correct Answer: A

Rationale: To add fractions, find a common denominator, which in this case is 40. Convert each fraction to have the common denominator: 7/8 = 35/40, 9/10 = 36/40, and 6/5 = 48/40. Add these fractions to get 119/40. Simplify this improper fraction to a mixed number, which is 3 & 39/40. Choice B and C are incorrect as they do not represent the sum of the fractions. Choice D is incorrect; the whole number part should be 3, not 2.

Correct Answer: D

Rationale: To find the value of x, cross multiply in the ratio 18:x=10:300. This gives 18 * 300 = 10 * x. Solving for x, x = 540. Therefore, the correct answer is D. Choice A (16), Choice B (180), and Choice C (30) are incorrect because they do not satisfy the proportion equation 18:x=10:300 when cross multiplied.

Correct Answer: D

Rationale: To divide mixed numbers, convert them to improper fractions. 5 & 3/4 = 23/4 and 1/2 = 2/1. So, 23/4 · 2/1 = 23/4 * 1/2 = 23/8 = 2 & 7/8. Therefore, 5 & 3/4 divided by 1/2 reduces to 11 & 1/2. Choices A, B, and C are incorrect because they do not represent the correct result of dividing 5 & 3/4 by 1/2.

Correct Answer: D

Rationale: To find the value of x in the given ratio and proportion, we can set up the equation as 15:2000=x:200. Cross multiply to get x * 2000 = 15 * 200. Simplifying this gives x = 1. Therefore, the correct answer is D, which is 1. Choice A (7), Choice B (0), and Choice C (7,777) are incorrect as they do not match the correct calculation of x.

Correct Answer: B

Rationale: The correct answer is B. When comparing 0.045 and 0.054, 0.045 is less than 0.054. Therefore, the correct relation is 'Less than.' Choice A ('Greater than') is incorrect because 0.045 is not greater than 0.054. Choice C ('Less than or equal to') is incorrect because 0.045 is strictly less than 0.054, not less than or equal to. Choice D ('Equal') is incorrect because 0.045 and 0.054 are not equal.