Question
The downstream and upstream speeds of a boat are 36 km/hr
and 28 km/hr, respectively. If the boatman covers (x + y) km upstream in 8 hours while the stream flows at double its usual speed, find the average of x and y.Solution
ATQ,
Let, speed of boat in still water and stream speed be B km/hour and s km/hour, respectively.
So, (B + s) = 36 … (i)
Also, (B – s) = 28 … (ii)
Solving equation (i), and (ii), we get,
B = 32 km/hour
s = 4 km/hour
According to question,
(x + y)/(B – 2s) = 8
(x + y) = 8 × (32 – 2 × 4) = 8 × 24 = 192 km
Therefore, average value of x and y = (x + y)/2 = 192/2 = 96 km
- Ravi divided 312 candies among his cousins Ayan, Rishi, and Mehul in the ratio 3:6:7 respectively. What is the difference between the candies received by M...
Mohini's Biology test had 250 questions i.e., 20 Macromolecules, 60 Homeostasis and 70 Immunology questions. Although she answered 70% of the Macromolec...
- Kiran shared 288 toffees among his three friends Sonu, Monu and Tanu in the ratio 2:3:7 respectively. Find how many more toffees Tanu received than Sonu.
- A box has ₹2, ₹1 and 25 paise coins in the ratio 3:5:7. If the total value is ₹446.25, how many 25-paise coins are there?
If ₹19,500 is divided among ‘A’, ‘B’, ‘C’, and ‘D’ in the ratio 6:8:5:7, then find the share of ‘C’.
...- The number of red and blue marbles in a box were in the ratio 6:11. There were 100 more blue marbles than red marbles. Later, 15 red and 25 blue marbles we...
- Manisha distributed 240 pencils among her three classmates—Nikhil, Arjun, and Sneha—in the ratio 2:3:5 respectively. Find the difference between the nu...
 If a student distributes sweets in the ratio of 1/2:1/3:1/4:1/5:1/6 among five of his friends A, B, C, D and E, then the total number (minimum) of swe...
Relevant for Exams:
