A businessman’ earning by 25% in one year but decreases by 4% in the next. Going by this pattern, after 5 years, his total earning would be Rs. 72000. What is his present earning?

The strength of a school increases and decreases in every alternate year by 10 %. It started with increase in 2000, then the strength of the school in 2003 as compared to that in 2000 was : 

Average of ten positive numbers  is x. If each number is increased by 12%  then x is increased by

A man loses 20% of his money. After spending 25% of the remainder, he has Rs.480 left with him. How much money did he originally have?

In an alloy, there is 12 % of copper, to get 69 kg of copper, how much alloy will be required? 

Sumit got 186 marks in Science, 158 marks in Hindi and 78 marks in Maths. The maximum marks in Science is 220, 180 in Hindi and 130 in Maths. What is his approximate total percentage marks?

In a village, each of the 60 % of families has a cow; each of the 30 % of families has a buffalo and each of the 15 % of families has both a cow and a buffalo. in all there are 96 families in the village. How many families do not have a cow or a buffalo?