There are 10 history books in a bookcase. When the number of books increases by x percent, the new number of history books is 24. What is the value of x?
Correct answer: D. 140
- A. 58
- B. 70
- C. 120
- D. 140
Explanation
To solve this problem, use the formula for percentage increase: new number = original number × (1 + x/100). Here, the original number of history books is 10, and the new number is 24. Set up the equation:24 = 10 × (1 + x/100)Divide both sides by 10 to isolate the percentage increase:2.4 = 1 + x/100Subtract 1 from both sides:1.4 = x/100Multiply both sides by 100 to solve for x:x = 140Therefore, the correct answer is Option D: 140. This means the number of books increased by 140%, making Option D correct. The other options (58, 70, and 120) do not satisfy the equation, as shown in their respective explanations.
Last updated
About Quantitative Reasoning
Quantitative reasoning applies arithmetic and basic algebra to numerical relationships, including percentages, ratios, averages, fractions, proportions, profit and loss, rates, time, work and measurement. Questions focus on translating words into equations, choosing an efficient method and checking whether the result is numerically reasonable.
Practise Quantitative Reasoning
505 free Quantitative Reasoning MCQs from Analytical and Logical Reasoning, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Analytical and Logical Reasoning questions like this
Analytical and Logical Reasoning is on 24 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
State whether a ∈ C, if {a} ⊂ A: i: A ⊆ B ii: B ⊆ C
If 2m=4x and 2w = 8x, what is m in terms of w?
The sum of the Series will be i) Tn = 7n -5 ii) 𝑑 = −5 iii) 𝑎 = 2 iv) 𝑛 = 16 Which two statements are sufficient to solve the given question?
If Lines AB||CD, then e = ?
Find the number of degrees in angle B?I. AC < BCII. Angle BCD = 100°III. Angle A + Angle B + Angle C = 180°IV. AB = BCV. ABC is an isosceles triangle Which two statements are sufficient to answer the question?