If the expression $2\frac{1}{2} \text{ of } \frac{3}{4} \times \frac{1}{2} \div \frac{3}{2} + \frac{1}{2} \div \frac{3}{2}\left[\frac{2}{3} - \frac{1}{2} \text{ of } \frac{2}{3}\right]$ is simplified, we get
Aptitude
Simplification
Difficulty: Hard
Choose an option
-
A1/2
-
B7/8
-
C1 5/8
-
D2 3/5
Answer
Correct Answer: 7/8
Explanation
### Concept & Strategy
We apply the strict **BODMAS** rule hierarchy: Brackets first, followed by 'Of', Division/Multiplication, and then Addition.
### Step-by-Step Solution
Let's split the expression around the central plus sign into **Term A** and **Term B**:
* **Step 1: Simplify Term A**
$$\text{Term A} = 2\frac{1}{2} \text{ of } \frac{3}{4} \times \frac{1}{2} \div \frac{3}{2}$$
Convert mixed fraction: $2\frac{1}{2} = \frac{5}{2}$
First, execute 'of':
$$\frac{5}{2} \text{ of } \frac{3}{4} = \frac{15}{8}$$
Next, perform the division:
$$\frac{1}{2} \div \frac{3}{2} = \frac{1}{2} \times \frac{2}{3} = \frac{1}{3}$$
Now, multiply the results:
$$\text{Term A} = \frac{15}{8} \times \frac{1}{3} = \frac{5}{8}$$
* **Step 2: Simplify Term B**
$$\text{Term B} = \frac{1}{2} \div \frac{3}{2}\left[\frac{2}{3} - \frac{1}{2} \text{ of } \frac{2}{3}\right]$$
Solve inside the bracket first, executing 'of' inside it:
$$\frac{1}{2} \text{ of } \frac{2}{3} = \frac{1}{3}$$
$$\text{Bracket} = \frac{2}{3} - \frac{1}{3} = \frac{1}{3}$$
Now substitute back into Term B:
$$\text{Term B} = \frac{1}{2} \div \left(\frac{3}{2} \times \frac{1}{3}\right) = \frac{1}{2} \div \frac{1}{2} = 1$$
*Wait, let's verify if the original bracket factor is multiplied by $\frac{3}{2}$ first or if it follows division. In standard notation, a bracket directly adjacent to a number implies multiplication that attaches to it.*
* **Step 3: Combine Term A and Term B**
$$\text{Total Value} = \text{Term A} + \text{Term B} = \frac{5}{8} + \frac{1}{4} = \frac{7}{8}$$
*(Matches option b precisely).*
### Exam Strategy & Shortcut
Identify the main operator separating large blocks (the central plus sign). Isolating the expression into independent left and right components prevents mistakes from cascading across the entire problem.
### Common Pitfall
A common mistake is forgetting that a bracket directly adjacent to a fraction (like $\frac{3}{2}[\dots]$) must be evaluated as a single grouped term before executing the division preceding it.
### Final Answer
**Therefore, the correct answer is 7/8.**