The following table shows the average speed (in km per hour) of five different…
2023
The following table shows the average speed (in km per hour) of five different trains A-E during six days of a week from Monday through Saturday. Some data is missing in the table (indicated as '-') that you are expected to calculate, if required. Based on the data in the table, answer the question that follows:
Train-wise speed (in km/hour) on different Days
Train | Monday | Tuesday | Wednesday | Thursday | Friday | Saturday |
|---|---|---|---|---|---|---|
A | 72 | 80 | - | 64 | 54 | - |
B | 88 | - | 80 | 84 | 72 | 90 |
C | 54 | 70 | 72 | - | 64 | 60 |
D | - | 120 | 95 | - | 90 | 110 |
E | 72 | 80 | 84 | 75 | - | - |
If train B covers a total distance of 3400 km during all six days in 40 hours, then its average speed during all six days together is ____% less than its average speed on Monday. (Rounded off to two digits after decimal)
Answer: C. 3.41 — ConceptAverage speed is total distance divided by total time. It represents one constant rate that would cover the same total distance in the same total time.…
- A.
6.33
- B.
4.67
- C.
3.41
- D.
5.25
Show answer & explanation
Correct answer: C
Concept
Average speed is total distance divided by total time. It represents one constant rate that would cover the same total distance in the same total time.
To find how much a new value is below a reference value, use percentage decrease = (reference value - new value) / reference value × 100.
Application
Compute the six-day combined average speed: 3400 / 40 = 85 km/h.
Read train B’s Monday average speed from the table: 88 km/h.
Find the decrease from Monday: 88 - 85 = 3 km/h.
Convert the decrease to a percentage of Monday’s speed: (3 / 88) × 100 = 3.40909...%, which rounds to 3.41%.
Cross-check
Reducing 88 km/h by 3.41% gives 88 × (1 - 3.41 / 100) = 84.9992 km/h, which rounds to the computed combined average of 85 km/h.
Result
Therefore, the six-day combined average speed is 3.41% less than the Monday average speed.