The Nobel Prize was awarded to Paul Muller for the discovery of which of the following pesticides?

What are the products formed when an aqueous solution of magnesium bicarbonate is boiled?

Typhoid fever is caused by which of the following?

Which one of the following compounds gives aspirin on reacting with acetic anhydride in the presence of conc. $H_2SO_4$?

$A$ die is thrown $10$ times. The probability that an odd number will come up at least one time is:

$A$ source of sound of frequency $640 ~Hz$ is moving at a velocity of $\frac{100}{3} ~m/s$ along a road,and is at an instant $30 ~m$ away from a point $A$ on the road (as shown in figure). $A$ person standing at $O$,$40 ~m$ away from the road,hears sound of apparent frequency $v^{\prime}$. The value of $v^{\prime}$ is (velocity of sound $= 340 ~m/s$). (in $~Hz$)