The speed of a boat downstream is 2.5 times the speed of the boat upstream. If the time taken by the boat for going 30 km downstream and the same distance upstream is 7 hours, then what is the speed (in km/h) of the boat downstream?
A sum was invested at simple interest at x% p.a. for 2(1/2) years. Had it been invested at (x + 3)% for the same time, it would have fetched ₹585 more. The simple interest on the same sum for 4(2/3) years at 14% p.a. is:
In a group of 108 persons, the ratio of the number of males and females is 5 : 4. The average height of the males is 158.7 cm and that of the females is cm. If the average height of all the persons in the group is 155.5 cm, then the value of x is:
A dealer bought an article at 10% discount on its marked price, and sold it at a price which was 15% above the marked price. The gain per cent (correct to the nearest iteger) is:
When x is subtracted from each of 24, 33, 20 and 26, the number so obtained in this order are in proportion. What is the mean proportional between (2x + 1) and (5x - 11) ?
