Find the length of the altitude of an equilateral triangle of side 3$\sqrt{3}$cm

First pipe can fill a tank in 12 hours. Second pipe can fill the same tank in 6 hours. Third pipe in 4 hours. How long will it take to fill the tank if all the 3 pipes are opened simultaneously?

If x² + 4y² = 4xy , then x : y is

A sum of Rs. 1,550 was lent partly at 5% and partly at 8% per annum at simpleinterest. The total interest received after 3 years was Rs. 300. The ratio of the money lent at 5% to that lent at 8% is

A sum of Rs. 800 amounts to Rs. 920 in 3 years at a simpleinterest. If the interest rate is increased by 3%. What would Rs. 800 amount to?

Match List 1 with List 2 and answer through the codes given below :

Identify the particle physicist through the clues given below
1. He won the Nobel Prize in physics for the year 2013 along with Francois Englert.
2. He won the Royal Societys Copley medal on 20, July 2015

Find out the values of a, b, c and d in the following equation
IO₃^- + aI^-+ bH⁺ $ \rightarrow$ cH₂O + dI₂

Find the pH of a buffer solution containing 0.20 mole per litre sodium acetate and 0.15 mole per litre acetic acid given that dissociation constant of acetic acid is 1.8x10^-5

Find the incorrect statement(s) from the following
(i) 2, 4, 5 trichlorophenoxyacetic acid is a herbicide
(ii) Thallium compounds are fumigants
(iii) Organo phosphorus insectides inhibit cholimesterase
(iv) Organo chlorine insectides are stomach poisons