Question
The question given below consists of a question and 3
statements given below it. You must decide whether the data provided in the statements is sufficient to answer the question. The ratio of efficiency of A and B is 2:3 and that of C and D is 1:4. Find the time taken by D alone to complete the work. I. A and D together complete the work in 6 days. II. A, B and C together complete the work in 5 days. III. B and D together complete the work in 4 days.Solution
ATQ, Let, the efficiency of A = 2a units/day And the efficiency of B = 3a units/day Let, the efficiency of C = b units/day And the efficiency of D = 4b units/day We have to find the time taken by D alone. From I A and D together complete the work in 6 days Total work = 6(2a + 4b) From II A, B and C together complete the work in 5 days Total work = 5(2a + 3a + b) = 5(5a + b) From III B and D together complete the work in 4 days Total work = 4(3a + 4b) From I and II 6(2a + 4b) = 5(5a + b) 12a + 24b = 25a + 5b 19b = 13a So, relation between a and b is obtained. From II and III 5(5a + b) = 4(3a + 4b) 25a + 5b = 12a + 16b 13a = 11b Again relation between a and b is obtained. From I and III 6(2a + 4b) = 4(3a + 4b) 12a + 24b = 12a + 16b 8b = 0 Not possible, so this pair is not useful for the intended data. Thus, any two statements are not sufficient here to uniquely determine D’s time. Hence, the correct option is E. None of these.
Two cyclists start together from the same point and move along a straight road in the same direction. One moves at 18 km/h and the other at 24 km/h. Aft...
Rafique had to cover 540 km in 24 hours. He covered the first 350 km at an average speed of 25 km/h. What should be Rafique's average speed for the rest...
Buses A and B are moving around a circular ground of radius 210 m. If the speeds of the buses A and B are 16 m/sec and 20 m/sec respectively, then what ...
- A cyclist starts from village 'M' at 8:00 AM towards village 'N' at 20 km/h. A biker starts from 'M' at 9:30 AM in the same direction at 60 km/h. Find the ...
Speed of a car and a bus is 30 km/h and 6 km/h, respectively. If the time taken by the car to cover a distance of ‘10x’ km is 2 hour less than time ...
If a person walks 25% more than of his usual speed, reaches his distance 90 minutes before. If the destination is 247.5 km away, then the usual speed of...
Ravi appointed 24 workers to finish a job in 18 days. After 9 days, he saw that only 1/3 of the job was completed. If 'n' is the number of additional wo...
1200 metres long train crosses a man who is moving in the same direction with a certain speed, in 30 seconds. If the same train can cross a tree in 20 s...
Buses A and B are moving around a circular ground of radius 280 m. If the speeds of the buses A and B are 12 m/sec and 20 m/sec respectively, then what ...
- A spy is 1.8 km ahead of an agent who begins to chase him. The agent runs at a speed of 12 m/s, while the spy runs at 8 m/s. How much time will the agent t...
