Question

A train starts its journey from point A towards point B. It travels 1/6^th of the total distance at constant speed and then covers the remaining distance at 5/8^th of earlier speed. If it covers the whole distance at 3/4^th of original speed then she reaches 30 minutes. Which of the below mentioned option is true?
1. D = 3.5V
2. D = 3V
3. D = 4.5V
4. D = 4V

Answer 1

Correct Answer - Option 2 : D = 3V

 

Calculation:

Let total distance be X

Case I:

⇒ Time taken to cover 1/6^th of distance = X/ (6× V)

⇒ Time taken to cover remaining distance = 5X/ (6 × 5 × V/ 8)

Case II:

⇒ Time taken to cover whole distance = X/ (3 × V/ 4)

⇒ (X/ 6V) + (40X/ 30V) = (4X/ 3V) + 0.5

⇒ (5X + 45X)/ 30V = (4X + 1.5V)/ 3V

⇒ 4.5X = 4X + 1.5V

⇒ 0.5X = 1.5V

⇒ X = 3.0 × V

∴ Distance D = 3 × V