Three solid metallic sphere whose radii are 3cm, x cm and 18cm respectively, are melted and recast into a single solid sphere of diameter 38cm. Then find the total surface area of the sphere with radius x cm?

The average age of a man and his son is 55 years. The ratio of their ages is 7 : 4, respectively. What will be the ratio of their ages after 6 years?

There are some boys and girls in a room. The square of the number of girls is 28 less than the square of the number of boys. If two more girls join then the number of boys and girls becomes equal, then what is the total number of boys and girls in the room?

P can do a piece of work in 60 days & Q can do the same work in 50 days. Find the ratio of working efficiencies of P to Q.

A woman buys a watch for Rs. 4,000 and sells it at a loss of 13%. What is the selling price of the watch?

Directions : Given here is a pie chart showing the cost of gold in 2010, 2011, 2012 and 2013. Study the chart and answer the following questions

The ratio of the price of gold in the two years 2010 and 2013 is

B walks at a speed of 9 km/h and after 9 hours of its start, C follows him on his cycle at a speed of 18 km/h. At what distance from the starting point will C catch B?

Two ship are on the opposite of a light house such that all three of them are collinear. The angels of depression of the two ships from the top of the light house are 30⁰ and 60⁰. If the ships are $$230 \sqrt { 3} \ $$ m apart, then find the height of the light house (in m).