The average marks of a student in an examination is 63, if he had scored 20 marks in geography and 2 more marks in history, his average marks would have been 65. How many subjects were there in the exam?

The average weight of 10 parcels is 1.7 kg. The average weight is reduced by 60 grams when a new parcel is added. How much is the weight of the new parcel?

The ratio of two number is 3 :5 . If 6 added to both the number then ratio become 2 :3 then find out the number?

If $$ {(x-5)^{2} +{(y-2)^{2}}+{(z-9)^{2}=0}}$$ then what is the value of (x+y-z)?

If an amount doubles automatically in 8 years, then what is the interest rate?

If the speed of the boat in still water is 20 km / h and the speed of the stream is 5 km / h, then how long will it take for the ferry to travel 100 km with the speed of the stream?

Last financial year, a car company sold 41,800 cars. The target is to sell 51,300 cars this year. What percentage would sales have to increase?

If the cost price of 28 items is equal to the selling price of 21 items, what is the profit percentage?