Question
Time is taken by two trains running in opposite
directions to cross a man standing on the platform in 36 seconds and 21 seconds respectively. It took 27 seconds for the trains to cross each other. What is the ratio of their speeds?Solution
Let the speed one train be x m/s and the speed of the second train be y m/s. Length of the first train = Speed × Time = 36x Length of second train = Speed × Time = 21y So, {(36x + 21y)/(x+y)} = 27 ⇒  36x + 21y = 27x + 27y ⇒ 9x = 6y Therefore, x:y = 2:3
Three boys runs around a circular track and takes 10 min, 30 min and 35 min respectively to complete the one round. When do they all come relatively to ...
The HCF of two numbers is 72, and their LCM is 2160. What is the sum of the numbers?
- The LCM and HCF of two numbers is 192 and 16 respectively. If the sum of the number is 112, then find the difference between the numbers.
LCM of two numbers is 10 times their HCF. The product of the numbers is 18000. What will be the maximum possible difference between the numbers?
Ratio of two numbers 5:9 and their LCM is 1260. Find the sum of the given two numbers.
- If the product of two numbers is 225 and their HCF is 15, then find the LCM of the given two numbers.
Let N be the greatest number that will divide 82, 105, 128 leaving the same remainder in each case. Then sum of the digits in N is:
A, B and C start running around a circular track and complete one round in 10, 15 and 25 seconds respectively. In how many seconds will the three meet a...
What is the unit digit of the number 'C' obtained by subtracting the largest two-digit prime number from the least common multiple (LCM) of all single-d...