Question
The average weight of x persons
is 33 kg. The average weight of (x−16) women is 45 kg, the average weight of (x−30) children is 40 kg, and the average weight of (x−35) men is 40 kg. Find the value of x, given that the total number of persons is the sum of men, women, and children.Solution
ATQ, Total weight of x persons = 35 × x = 35x kg Total weight of (x - 16) women = 45 × (x -16) = 45x - 720 kg Total weight of (x - 30) children = 40 × (x - 30) = 40x - 1200 kg Total weight of (x - 33) men = 40 × (x - 33) = 40x - 1320 kg According to the question, 35x = 45x - 720 + 40x - 1200 + 40x - 1320 35x = 125x - 3240 90x = 3240 x = 36
- A boat covers 90 km downstream and 70 km upstream in a total time of 10 hours. How much time will it take to travel 126 km downstream and 98 km upstream?
Ratio of speed of boat in downstream and speed of stream is 7:5, if speed of current is 5 km/hr, then find distance travelled (in km) upstream in 4 hours.
A boat can travel 7.2 km upstream in 18 min. If the ratio of the speed of the boat in still water to the speed of the stream is 7:1. How much time will ...
A man can row at 30 km/hr in still water. If the velocity of current is 6 km/hr and it takes him 1 hour to row to a place and come back, how far is the ...
The speed of a boat in still water is twice the speed of the current. If the boat takes 10 hours to cover 150 km upstream, then find the time taken by t...
A motor boat goes downstream from point A to B ,which is 36 km away from point A, and then returns to A. If actual speed of the boat in still water is 7...
The speed of a boat in still water is 12 times the speed of the stream. If the difference between the upstream and downstream speed of the boats is 20 k...
A boat travels 48 km downstream in 4 hours and 24 km upstream in 6 hours. What is the speed of the boat in still water?
A boy can swim in water with a speed of 12 km/hr in still water. If the speed of the stream is 6 km/hr, what will be the time taken by the boy to cover ...
The ratio of the speed of the boat in upstream to that of in downstream is 7:10, respectively. If the speed of the current is 12 km/h, then find the spe...