Question
A train travels from station βPβ to station βQβ
at a constant speed. If its speed was increased by 20 km/h, it would have taken 1 hour less to cover the distance. It would have taken further 30 minutes less if the speed was further increased by 20 km/h. The distance between station βPβ and station βQβ is:Solution
According to the question, Let the original speed of the train be βxβ km/h and the original time taken to reach the destination be βtβ hours. So, the distance between station βPβ and βQβ = x Γ t = xt km So, xt/(x + 20) = t β 1..........................(1) And, xt/(x + 40) = t β 1 β 0.5 Or, xt/(x + 40) = t β 1.5........................(2) Dividing equation (1) by equation (2), we get (x + 40)/(x + 20) = (t β 1)/(t β 1.5) So, xt β 30 β 5x + 20t = xt + 20t β x β 20 Or, 20t β 5x = 10 Or, x = 4/5 Γ (20t β 10) Putting the value of βxβ in equation (1), we get 40tΒ² β 80t = 40tΒ² β 110t + 70 Or, t = 3 So, x = 4/5 Γ (60 β 10) = 40 Desired distance = 3 Γ 40 = 120 km
- In Delhi, he (a)/ suddenly came across many (b)/ of his friends who had settled there. (c) / No Error (d) 
- I have been knowing(1)/ him for the last(2)/ five years but now I donβt(3)/ know where he lives.(4) 
- Read each sentence to find out whether there is any grammatical error in it. The error, if any, will be in one part of the sentence. Mark the part with... 
- Direction : In each of the questions, a sentence has been divided into four parts, one of which may contain an error. Identify that fragment and mark ... 
- Select the word that is spelled INCORRECTLY 
- Over the last year, the record of implementation (1) of the steps in the peace accord has been patchy (2) , though major strides were made in the form o... 
- Given below is a sentence with an error. The error is in one part of the sentence. Below the sentence are given the options containing the parts of the sen...
- Identify the segment in the sentence, which contains the grammatical error - No matter he tries hard he cannot play the guitar. 
- The lemons in our neighborβs garden hanged invitingly, and they took me back to those lazy summer afternoons where we would squander them away in pit... 
- Beside foggy conditions, (1) / the minimum temperature sharply fall in (2)/ the region as the mercury hovered (3)/ among four degrees below normal to (4...