Name the blood cells,whose reduction in number can cause clotting disorder,leading to excessive loss of blood from the body.

What is the percentage of lead in a lead pencil (in $,\%$)?

An increase in equivalent conductance of a strong electrolyte with dilution is mainly due to

$A$ ball $A$ of mass $m$ moving along the positive $x$-direction with kinetic energy $K$ and momentum $p$ undergoes an elastic head-on collision with a stationary ball $B$ of mass $M$. After the collision,ball $A$ moves along the negative $x$-direction with kinetic energy $K/9$. The final momentum of ball $B$ is:

The number and type of bonds between $2$ carbon atoms in $CaC_2$ are:

$A$ and $B$ are two radioactive substances whose half-lives are $1$ and $2$ years respectively. Initially, $10 \, g$ of $A$ and $1 \, g$ of $B$ are taken. The time (approximate) after which they will have the same quantity remaining is ........... $years$.