Question
The average of the first and second numbers is 45, while
the average of the second and third numbers is 55. If the sum of the first and third numbers is 94, then find the first number.Solution
ATQ, Let, the 1st, 2nd and 3rd number be x, y, and z respectively. According to the question, x + y = 90 ... (1) y + z = 110 ... (2) From equation (1) and (2) z β x = 20.... (3) z + x = 94 ... (4) On solving equation (3) and (4), we get z - x = 20.......(3) x + z = 94.......(4) Adding these two equations: 2z = 114 z= 57 Substituting z = 57 into eq.(4) x + 57 = 94 x = 37
The speed of the stream is 14 km/h. Boat βAβ covers 64 km distance against the stream in 4 hours and boat βBβ covers 95 km distance against the ...
- A boat takes 4 hours to travel a distance of '4D' km upstream. However, it covers a distance of (4D + 8) km downstream in just 2 hours. Given that the boat...
If Boat goes 80 km upstream in 4 hours and 60 km downstream in 2 hours, then the speed of the boat in still water is
A motorboat in still water travels at a speed of 16 km/hr. It goes 27 km upstream in 2 hour 15 minutes. The time taken by it to cover the same distance ...
A man can row 16 km/hr in still water. If the speed of the current is 4 km/hr, it takes 5 hours more in upstream than in the downstream for the same dis...
A boat can cover a distance of 210 km downstream with the current in 5 hours. It takes an additional 2.5 hours to return the same...
A Submarine undertakes a journey, covering a distance of 44.8 km against the current in precisely 2 hours and 48 minutes. The challenging task at hand i...
A boat makes a journey from point P to point Q and return back in 6 hr 40 min. One way it travels with the stream and on the return it travel against th...
The speed of a boat in calm water is 4 km/hr greater than the speed of the stream. The boat travels a distance of 280 km downstream and 200 km upstream ...
A car can cover a β2dβ km distance at the speed of βBβ km/h in 30 hours. The speed of the boat in still water and the speed of the stream are οΏ½...
Relevant for Exams:
