A number is first decreased by 10% and then increased by 10%. The number so obtained is 50 less than the original number. The original number is:

The price of petrol is increased by 25%. By how much percent a car owner should reduce his consumption of petrol so that the expenditure on petrol would not be increased?

Two pipes of length 1.5 m and 1.2 m are to be cut into equal pieces without leaving any extra length of pipes. The greatest length of the pipe pieces of same size which can be cut from these two lengths will be

Three bells ring at interval of 36 seconds, 40 seconds and 48 seconds respectively. They start ringing together at a par- ticular time They will ring to gether after every 

The LCM of four consecutive numbers is 60 The sum of the first two numbers is equal to the fourth number. What is the sum of four numbers? 

The ratio of HCF and LCM of two numbers a and b is 1:30 and the difference between the HCF and LCM is 493. Find the possible number of pairs of a and b.

The number between 4000 and 5000 that is divisible by each of 12, 18, 21 and 32 is 

The difference between the greatest and least prime numbers which are less than 100 is: