UGC NET Questions (Paper – 1)

Average speed is calculated as total distance divided by total time taken. Here, the distance is 120 km and the time is 3 hours. Dividing 120 by 3 gives 40 km/h. Therefore, the car’s average speed over the journey is 40 km/h.

Option A:
Option A is correct because the straightforward computation 120 ÷ 3 = 40 yields the average speed. This aligns with the definition of speed as distance per unit time. In exam settings, quickly identifying such basic calculations saves valuable time for more complex questions.

Option B:
An average speed of 30 km/h would correspond to travelling 90 km in 3 hours, not 120 km. Since the actual distance travelled is greater, this option underestimates the speed. Hence, it is incorrect.

Option C:
A speed of 50 km/h over 3 hours would give a distance of 150 km, which is higher than the given 120 km. This shows that 50 km/h is too high for the conditions described.

Option D:
A speed of 60 km/h for 3 hours would produce a distance of 180 km, which is much larger than 120 km. Therefore, 60 km/h does not match the data and cannot be the correct answer.

Speed measures how fast an object moves and is defined mathematically as distance travelled per unit time. This can be written as speed = distance ÷ time, which is equivalent to the ratio of distance to time. In aptitude questions, common units include km/h and m/s based on this definition. Therefore, the correct description is the ratio of distance to time.

Option A:
Time to distance would represent the inverse ratio, which tells how much time is taken per unit distance rather than how much distance is covered per unit time. While this can be useful in some contexts, it is not the standard definition of speed. Hence, this option is incorrect.

Option B:
Work to time describes the rate of doing work, usually called "work rate" or "power," not speed. This ratio is relevant in time and work problems, but it does not relate to motion along a path. Therefore, it does not fit the context of speed.

Option C:
Distance to work is not a meaningful physical ratio in basic quantitative aptitude. It does not correspond to any standard concept in time and distance or mechanics. Since the question is specifically about speed, this option is irrelevant and incorrect.

Option D:
Distance to time is correct because it captures the idea of how far an object moves in a given amount of time. For example, if a vehicle travels 60 km in 2 hours, its speed is 60 ÷ 2 = 30 km/h. This understanding is essential for solving many numerical problems in UGC NET Paper 1.