Question
Find and compare the speeds of
the boats in still water based on the given conditions. Boat A takes the same amount of time to travel 2x km upstream as it does to travel 3x km downstream. Boat B takes the same amount of time to travel 3y km upstream as it does to travel 5y km downstream. Boat C takes the same amount of time to travel 5z km upstream as it does to travel 7z km downstream. Quantity I: Boat A covers 144 km downstream and then returns to the starting point, completing the round trip in 20 hours. Find the speed of Boat A in still water. Quantity II: Boat B covers 150 km downstream and returns to the starting point, completing the round trip in 16 hours. Find the speed of Boat B in still water. Quantity III: Boat C covers 140 km downstream and returns to the starting point, completing the round trip in 12 hours. Find the speed of Boat C in still water. In the question, three quantities i.e. Quantity I, Quantity II and Quantity III are given. Solve the given quantities to establish the correct relation between them and choose the correct optionSolution
ATQ, For Boat A, Downstream Speed : Upstream Speed = 3x : 2x = 3 : 2 For Boat B, Downstream Speed : Upstream Speed = 5y : 3y = 5 : 3 For Boat C, Downstream Speed : Upstream Speed = 7z : 5z = 7 : 5 Quantity I, For Boat A, Downstream Speed = 3a km/hr Upstream Speed = 2a km/hr 144/3a + 144/2a = 20 48/a + 72/a = 20 120/a = 20 a = 6 Speed of Boat A in still water = (3a + 2a)/2 = 5a/2 = 2.5 × 6 = 15 km/hr Quantity II, For Boat B, Downstream Speed = 5b km/hr Upstream Speed = 3b km/hr 150/5b + 150/3b = 16 30/b + 50/b = 16 80/b = 16 b = 5 Speed of Boat b in still water = (5b + 3b)/2 = 8b/2 = 4 × 5 = 20 km/hr Quantity III, For Boat C, Downstream Speed = 7c km/hr Upstream Speed = 5c km/hr 140/7c + 140/5c = 12 20/c + 28/c = 12 48/c = 12 c = 4 Speed of Boat C in still water = (7c + 5c)/2 = 12c/2 = 6 × 4 = 24 km/hr Quantity I < Quantity II < Quantity III
The average age of (x + 4) students is 14 years. When a tutor aged 30 years is included, the average increases by 1 year. Find x% of 900.
The ratio of the present age of A to that of B is 7:9. Six years ago the ratio of 1/3 of A’s age at that time and 1/3 of B’s age at that time was 1:...
Shivani is 6 years younger than Deepika and Deepika is 6 years younger than Mohani. After 6 years the ratio of Shivani’s age and Mohani’s age will b...
Shalini is younger than Rashi by 3 years. If the ratio of Shalini and Rashi ages is 9:10 respectively, then find the age of Shalini.
18 years ago the average age of a family of four members was 45 years. Two children were born in that span of 18 years. The present average age of the f...
At present Meena is eight times her daughter’s age. Eight years from now, the ratio of the ages of Meena and her daughter will be 9 : 2 respective...
When 15 years is subtracted from the present age of A and the obtained result is divided by 4, then the present age of his nephew is obtained. If the pr...
The average of the current ages of Armaan, Biju, Chinky, and Danny is 31 years. Two years from now, the average age of Armaan and Biju will be 22 years....
The present age ratio between 'A' and 'B' is 6:4 respectively. If the sum of 'A's age 3 years ago and 'B's age 8 years from now is 50 years, what is the...
A is 3 years older than B while C is 4 years younger than B. The ratio of age of A, 8 years hence and age of B, 6 years ago is 5:4. What was age of C, 1...
Relevant for Exams:
