Rani goes to school from her house in 30 minutes. Raja takes 45 minutes in covering the same distance. Find the ratio between time taken by Rani and Raja.
Aptitude
Time and Distance
Difficulty: Easy
Choose an option
-
A2 : 3
-
B4 : 3
-
C3 : 2
-
D1 : 3
Answer
Correct Answer: 2 : 3
Explanation
### Concept & Simple Ratios
A ratio compares two quantities of the same kind. To find the ratio between two times, simply place them in a fraction and simplify to its lowest terms.
$$Ratio = \frac{\text{Time}_1}{\text{Time}_2}$$
### Step-by-Step Solution
1. Time taken by Rani = 30 minutes.
2. Time taken by Raja = 45 minutes.
3. Form the ratio of Rani's time to Raja's time:
$$Ratio = \frac{30}{45}$$
4. Simplify the ratio by dividing the numerator and denominator by their greatest common divisor (15):
$$Ratio = \frac{30 \div 15}{45 \div 15} = \frac{2}{3}$$
5. Expressed as a ratio, this is 2 : 3.
### Exam Strategy & Shortcut
Both numbers end in 5 or 0, making them multiples of 5, but quickly scanning for larger multiples reveals they are both part of the 15 times table ($15 \times 2 = 30$, $15 \times 3 = 45$). This gives the simplified ratio of 2:3 instantly.
### Common Pitfall
Inverting the ratio by accident. The question asks for "Rani and Raja" in that specific order. Writing 3:2 (Raja to Rani) would be incorrect.
### Final Answer
Therefore, the correct answer is **2 : 3**.