If 80 litres of milk solution has 60% milk in it, then how much milk should be added to make milk 80% in the solution?

Rahul purchased two different kinds of alcohol. In the first mixture the ratio of alcohol to water is 3:4 and in the second mixture it  is 5:6. If he mixes the two given mixture and makes a third mixture of 18 litres in which the ratio of alcohol to water is 4:5, the quantity of first mixture (whose ratio is 3:4) is required to make the 18 litres of the third kind of mixture is:

The difference between the average of three consecutive even numbers and the average of the next two consecutive even number is 5. What is first even number?

If the seven-digit number 52A6B7C is divisible by 33, and A, B, C are primes, then the maximum value of 2A + 3B + C is:

Two trains starts from place A and B, 450 km apart towards each other. Both trains start simultaneously. A crow sitting on one train start flying at the same time towards the other train and as soon as it reaches the second train, it flies back to the first train and it continues in this manner flying backward and forwards from one train to the other until the train meet. Both train travel  at a speed of 45 km / h and the crow flies at 100 km / h total distance covered by the crow will be