A mixture of petrol and kerosene weighing 5 kg contains 5% kerosene. How much more kerosene (approx.) must be added into it to make it 10%?

Find the value of √[(2 + √3)/(2 − √3)], correct to three places of decimal.

A student who gets 20% marks fails by 20 marks, but another student who gets 36% marks gets 44 marks more than minimum passing marks. Find the maximum number of marks and percentage necessary for passing.

The area of a triangular metal plate with base 88 cm and altitude 64 cm is to be reduced to one-fourth of its original area by making a hole of circular shape at the center. The radius of this hole will be:

If 26 horses or 20 bullocks eat up the fodder in store in 170 days, in what time will 10 horses and 8 bullocks finish the same quantity of fodder?

By selling mangoes at the rate of 64 for Rs. 2,000, the vendor loses 40%. How many should he sell for Rs. 1000 so as to gain 20%?

A boat covers 24 km upstream and 72 km downstream in 8 hours, while it covers 48 km upstream and 108 km downstream in 14 hours. Find the speed of the boat in still water and the speed of the stream respectively.

The average age of three men is 50 years and their ages are in the proportion 3:5:7. The age of the youngest man is:

A shopkeeper sells rice at the cost price, but uses a false weight. He gains 20% in this process. What weight does he use for one kilogram?