Copper sulphate crystals available in the market are blue coloured crystals. By careful heating, they turn to white colour. Which one of the following is responsible for the blue colour ?

For election to the Lok Sabha, a nomination paper can be filed by

Miscellaneous · Easy

In a month if the seventh day is three days earlier than Saturday,then the nineteenth day of the month will be a

Miscellaneous · Easy

Which among the following events happened earliest ?

Miscellaneous · Easy

An 80-litre solution of alcohol and water has 75% alcohol. How much water (in litres) must be added to bring down the concentration of alcohol to 60%?

Miscellaneous · Easy