Advertisements
Advertisements
प्रश्न
While boarding an aeroplane, a passengers got hurt. The pilot showing promptness and concern, made arrangements to hospitalize the injured and so the plane started late by 30
minutes. To reach the destination, 1500 km away, in time, the pilot increased the speed by 100 km/hour. Find the original speed of the plane.
Do you appreciate the values shown by the pilot, namely promptness in providing help to
the injured and his efforts to reach in time?
उत्तर
Let the original speed of the plane be x km/h.
∴Actual speed of the plane `=(x+100)`Km/h
Distance of the journey =1500 km
Time taken to reach the destination at original speed=`1500/x h`
`(Time= (Distance)/(Speed))`
Time taken to reach the destination at actual speed=`1500/(x+100) h`
According to the given condition,
Time taken to reach the destination at original speed = Time taken to reach the destination at actual speed + 30 min
∴` 1500/x=1500/(x+100)+1/2`
⇒`1500/x-1500/(x+100)=1/2`
⇒`(1500x+150000-1500x)/(x(x+100))=1/2`
⇒`150000/(x^2+100x)=1/2`
⇒`x^2+100x=300000`
⇒`x^2+100x=300000=0`
⇒`x^2+600x-500x-300000=0`
⇒`x(x+600)-500(x+600)=0`
⇒`(x+600)(x-500)=0`
⇒`x+600=0 or x-500=0`
⇒`x=-600 or x=500`
∴ `x=500` (Speed cannot be negative)
Hence, the original speed of the plane is 500 km/h.
Yes, we appreciate the values shown by the pilot, namely promptness in providing help to the injured and his efforts to reach in time. This reflects the caring nature of the pilot and
his dedication to the work.
APPEARS IN
संबंधित प्रश्न
The sum of a number and its reciprocal is `2 1/30` Find the number.
In a class test, the sum of Kamal’s marks in mathematics and English is 40. Had he got 3 marks more in mathematics and 4 marks less in English, the product of the marks would have been 360. Find his marks in two subjects separately.
The sum of the ages of a boy and his brother is 25 years, and the product of their ages in years is 126. Find their ages.
A motor boat whose speed in still water is 178 km/hr, takes 1 hour more to go 24 km upstream than to return to the same spot. Find the speed of the stream
A motorboat whose speed is 9 km/hr in still water, goes 15 km downstream and comes back in a total time of 3 hours 45 minutes. Find the speed of the stream.
Two water taps together can fill a tank in 6 hours. The tap of larger diameter takes 9 hours less than the smaller one to fill the tank separately. Find the time which each tap can separately fill the tank.
The length of a hall is 3 meter more than its breadth. If the area of the hall is 238 sq meters, calculate its length and breadth.
Raj and Ajay are very close friends. Both the families decide to go to Ranikhet by their own cars. Raj’s car travels at a speed of x km/h while Ajay’s car travels 5 km/h faster than Raj’s car. Raj took 4 hours more than Ajay to complete the journey of 400 km.
What will be the distance covered by Ajay’s car in two hours?
Raj and Ajay are very close friends. Both the families decide to go to Ranikhet by their own cars. Raj’s car travels at a speed of x km/h while Ajay’s car travels 5 km/h faster than Raj’s car. Raj took 4 hours more than Ajay to complete the journey of 400 km.
Which of the following quadratic equation describe the speed of Raj’s car?
The speed of a motorboat is 20 km/hr. For covering the distance of 15 km the boat took 1 hour more upstream than downstream.
What is the relation between speed, distance and time?