Two girls move in opposite directions, one from A to B and other from B to A.…
2024
Two girls move in opposite directions, one from A to B and other from B to A. The girl from A reaches the destination in 16 hrs and girl from B reaches her destination in 25 hrs, after having met. If former's speed is 25 km/hr, what will be the speed of latter?
- A.
10 km/hr
- B.
12 km/hr
- C.
16 km/hr
- D.
20 km/hr
Attempted by 1 students.
Show answer & explanation
Correct answer: D
Step-by-Step Solution
When two objects meet and then continue to their respective destinations, the relationship between their speeds (Sa, Sb) and the time taken to reach their destinations after meeting (ta, tb) is given by the formula:
Sa / Sb = sqrt(tb / ta)
Identify the given values:
Speed of the first girl (Sa) = 25 km/hr
Time taken by the first girl to reach destination after meeting (ta) = 16 hours
Time taken by the second girl to reach destination after meeting (tb) = 25 hours
Let the speed of the second girl be Sb.
Apply the formula:
25 / Sb = sqrt(25 / 16)
25 / Sb = 5 / 4
Solve for Sb:
5 * Sb = 25 * 4
5 * Sb = 100
Sb = 20 km/hr