A train covers a certain distance at a speed of 40 km/h and the next same distance with a speed of 70 km/h and the next same distance with a speed of 120 km/h. find the average speed?
Since the distance is same in all the conditions. Therefore, Average speed = 3xyz/(xy + yz + zx) Average speed = 3 x 40 x 70 x 120/(40 x 70 + 70 x 120 + 40 x 120) Average speed = 3 x 40 x 70 x 120/(2800 + 8400 + 4800) = 1008000/16000 = 63 km/hr
At present Meena is eight times her daughter’s age. Eight years from now, the ratio of the ages of Meena and her daughter will be 9 : 2 respective...
The current ratio of the ages of 'Armaan' and 'Bittu' is such that six years from now, it will be 5:4, respectively. Presently, 'Chetna's age exceeds 'B...
Present age of ‘A’ is 25% more than that of ‘B’. If 9 years hence from now, ‘B’ will be 6 years younger than ‘A’, then find the sum of p...
The ratio of A and B present age is 3:2. The product of their ages is 2400. What will be the ratio of their ages after 5 years?
Two years ago, the combined ages of Armaan and Bikash equaled Chetna's age at that time. Ten years ago, Armaan was twice as old as Bikash. If, in five y...
The ratio of the present ages of ‘A’ and ‘B’ is 5:6, respectively. Three years hence from now, the age of ‘B’ will be 21 years. If the avera...
Present age of ‘A’ is 40% more than that of ‘B’. If 11 years hence from now, ‘B’ will be 5 years younger than ‘A’, then find the sum of ...
A is 2 years older than B while C is 3 years younger than B. The ratio of age of A, 5 years hence and age of B, 4 years ago is 5:4. What was age of C, 1...
A’s age is the sixth part of his father’s age. After 10 years, the age of A’s father will be twice the age of B. If B’s 4th birt...
Rohan's present age is 3/7 times the age of his mother. After four years, he will be one- half of the age of his mother. How old is his mother at present?
