Question

Two ducks move along the circumference of a cir-cular pond in the same direction and come alongside each other every 54 minutes. If they moved with the same speeds in the opposite directions, they would meet every 9 minutes. It is known that when the ducks moved along the cicumference in opposite directions, the distance between them decreased from 54 to 14 feet every 48 seconds. What is the speed of the slower duck? (a) 20 feet/min (b) 15 feet/min (c) 30 feet/min (d) 20.83 feet/min

Answer 1

Answer:

since distance decrease from 54 to 14, distance covered = 40 feet (54-14)

time taken to cover distance = 48 sec = 48/60 min

since they move in opposite directions, relative speed = S1 + S2

therefore, S1 + S2 = 40/(48/60)= 50 _____(1)

from initial part of Question,

S1 - S2 = d/54 (as in same direction they take 54 mins to meet, considering relative speed)_______(2)

S1 + S2 = d/9 ( similarly given in Ques for opposite direction)______(3)

d is the total circumference of pond

from (1) & (3)

50 = d/9 => d = 450

(3) - (2)=>

2× S2 = 5d/54

substitute d= 450 you get S2 = 20.83 feet/min

thank me latter

Answer 2

Step-by-step explanation:

Two ducks move along the circumference of a cir-cular pond in the same direction and come alongside each other every 54 minutes. If they moved with the same speeds in the opposite directions, they would meet every 9 minutes. It is known that when the ducks moved along the cicumference in opposite directions, the distance between them decreased from 54 to 14 feet every 48 seconds. What is the speed of the slower duck? (a) 20 feet/min (b) 15 feet/min (c) 30 feet/min (d) 20.83 feet/min