Geography books are never together.
No. of when Geography book are always together = 7! × 6! Total no. of ways when all the books are arranged without any condition = 12! No. of when Geography book are never together = 12! – (7! × 6!)
One property of ammonia is
Which of the following is used to increase the antiknocking property of petrol?
Of the following which one pollutes the air of abig city?
The chief source of naphthalene is
The most abundant constituent of atmospheric air is
Bakelite is a copolymer of Phenol and
The electronic configuration of an atom having atomic number 20 is
Taj Mahal is greatly affected due to:
When Hydrogen starts burning in air it produces?
The process of covering water pipes made of Iron with Zinc layer to prevent corrosion is called:
