Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?

A student multiplied a number by 3/5 instead of 5/3, What is the percentage error in the calculation ?

Insert the missing number.
7, 26, 63, 124, 215, 342, (....) 

A clock is set right at 8 a.m. The clock gains 10 minutes in 24 hours will be the true time when the clock indicates 1 p.m. on the following day?

If 20% of a = b, then b% of 20 is the same as

8 litres are drawn from a cask full of wine and is then filled with water. This operation is performed three more times. The ratio of the quantity of wine now left in cask to that of the water is 16 : 65. How much wine the cask hold originally?

A, B and C can do a piece of work in 24 days, 30 days and 40 days respectively. They began the work together but C left 4 days before the completion of the work. In how many days was the work completed?

Insert the missing number.
16, 33, 65, 131, 261, (....)

If the length of the diagonal of a square is 20cm,then its perimeter must be

Out of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed?