If the regression coefficients of x on y and y on x are -1/4 and -1/9 respectively, then what is the correlation coefficient between x and y?
 r= -1/6. (The sign of r depends on the sign of regression coefficients. It takes the sign of the regression coefficients always)
A motorbike travelled for the first 180 km at a certain speed in 4 hours. After that, the speed of the motorbike decreased by 5 km/h. If the motorbike t...
Robert started his journey on Monday and travelled at constant speed. Next day by 10.30 am, he had covered 4/7 of his whole journey and on the same day ...
A train covers a certain distance at a speed of 20 km/h and the next same distance with a speed of 35 km/h and the next same distance with a speed of 60...
A can walk a certain distance in 11 days when he rests 8 hours a day. How long will he take to walk twice the distance, twice as fast and resting twice ...
Two vehicles, named as 'X' and 'Y', travel along side-by-side paths but in opposite directions. The length of vehicle 'Y' surpasses that of 'X' by 12.5%...
A boat goes downstream for 44 km and immediately return. It took the boat twice as long as to make the return trip. If the speed of river flow were twic...
Train A takes 45 minutes more than train B to travel a distance of 450 km. Due to engine trouble speed of train B falls by a quarter, so it takes 30 min...
The speed of a train is 54 km/hr and it takes 14 seconds to cross a man. Find the time taken by train to cross a platform if the ratio of the length of ...
Ratio of speeds of ‘A’ and ‘B’ is 11:13, respectively. If they participate in a 130-metre race and ‘B’ gives ‘A’, a head start of ‘mâ€...
If the sum of upstream and downstream speed is 32 km/hr and the speed of the current is 6 km/hr. Then find time taken to cover 44 km in downward?
