Question
The upstream speed of a boat is 12 km/hr. If the boat
covers 180 km downstream in 5 hours, find the speed of the current.Solution
Let the speed of the current be βxβ km/hr Therefore, speed of the boat in still water = (x + 12) km/hr According to the question, (x + 12 + x) = 180/5 Or, 2x + 12 = 36 Or, 2x = 24 Or, x = 12 Therefore, speed of the current = 12 km/hr
- βXβ, βYβ and βZβ jointly hired a machine to do a task. If they used it for 6, 9, and 5 hours respectively, and the total cost came to Rs. 1000,...
- Suppose 6A = 8B = 15C, then find the value of (A:B:C) . 
- In an orchard, the ratio of the number of mango and lichi trees is 4:7, respectively. Also, there are few apple trees in the orchard which is 50% more t... 
- There are 120 balloons of three different colours in a box. The ratio of red balloons to yellow balloons is 2:3, and the ratio of red balloons to green ... 
- Ratio of number of boys to girls in a school of 840 students is 5:3. Ratio of number of boys who passed to those who failed in an exam is 11:4 whereas rati...
- A bag contains red and yellow marbles in the ratio 4:5, respectively. Also, the ratio of yellow to green marbles is 1:3. If the total number of marbles in ...
- A school has a total of 600 students. The ratio of boys to girls is 3:5. If 40% of the boys and 20% of the girls participated in a sports event, how man... 
- The ratio of two numbers is 3: 5. If eight is added to the first, and seven to the second, then the ratio becomes 2:3. What will be the ratio become if... 
- Radius of base of a hollow cone is 8 cm and its height is 15 cm. A sphere of largest radius is put inside the cone. What is the ratio of radius of base ... 
- If the ratio of the sum invested and simple interest received after 1 year is 25:9 respectively, then find the rate of interest.