Question
A train covers a certain distance at a speed of 12 km/h
and the next same distance with a speed of 21 km/h and the next same distance with a speed of 36 km/h. find the average speed?Solution
Since the distance is same in all the conditions. Therefore, Average speed = 3xyz/(xy + yz + zx) Average speed = 3 x 12 x 21 x 36/(12 x 21 + 21 x 36 + 12 x 36) Average speed = 3 x 12 x 21 x 36/(252 + 756 + 432) = 27216/1440 = 18.9 km/hr  Â
 If 1.5x = 0.04y, then the value of
Arvind's age after 19 years will be 67 years. Ravi is 4 years older than Arvind. The ratio of present ages of Samar and Ravi is 9:13. Find the age of Sa...
What is the highest possible sum of (m + n) if the number '9m813n2' is divisible by 12?
What least number must be added to 6834 to get a number exactly divisible by 18?
Nikhil has joined Facebook and has 18 friends and each of these friends has 25 friends. Later, it is found that at least two of his friends know each o...
- The sum of two numbers is 80 whereas the sum of their reciprocals is (22/11). Find the square of the product of the two numbers.
Divisor is 7 times of Quotient and 3 times of its remainder. If the remainder is 7. Find the dividend?
Find the sum of all factors of 60?
- The combined total of two numbers is 105. Their LCM and HCF are 315 and 5 respectively. What is the smaller number?
Relevant for Exams:
