A and B are standing at either ends of the diagonal of a rectangular room. B starts walking along the diagonal to reach the other end of the diagonal. A walk along the length and breadth to reach the other end of the diagonal. A takes 7 seconds to travel which is 2 seconds more than the time taken by B. B travelled 20 m. Find the perimeter of the room, given that speed of A and B is same.
A and B are standing at either ends of the diagonal of a rectangular room. B starts walking along the diagonal to reach the other end of the diagonal. A walk along the length and breadth to reach the other end of the diagonal. A takes 7 seconds to travel which is 2 seconds more than the time taken by B. B travelled 20 m. Find the perimeter of the room, given that speed of A and B is same. Correct Answer 56 m
Given:
A and B are standing at either ends of the diagonal of a rectangular room. B starts walking along the diagonal to reach the other end of the diagonal. A walk along the length and breadth to reach the other end of the diagonal. A takes 7 seconds to travel which is 2 seconds more than the time taken by B. B travelled 20 m.
Formula:
Distance = speed × time
Calculation:
Let the length and breadth of the rectangular room be l and b respectively.
B took 5 seconds.
⇒ Speed of B = 20/5 = 4 m/s
Speed of A = 4m/s
Distance A travelled = 4 × 7 = 28 m
Distance B travelled = 20 m
⇒ l + b = 28
⇒ l2 + b2 = 202
⇒ l2 + (28 – l)2 = 20
⇒ l = 16 and b = 12
∴ required perimeter = 2 × (l + b) = 2 × (16 + 12) = 2 × 28 = 56 m