The variance of $20$ observations is $5$. If each observation is multiplied by $2$,then the variance of the resulting observations is:

Two finite sets have $m$ and $n$ elements respectively. If the number of subsets of the first set is $56$ more than the number of subsets of the second set,then the values of $m$ and $n$ are:

Lactose is composed of ......... .

Which of the following compounds is electron-deficient?

If the equilibrium constant for the reaction,$H_{2(g)} + I_{2(g)} \rightleftharpoons 2 HI_{(g)}$ is $K$,what is the equilibrium constant of $HI_{(g)} \rightleftharpoons \frac{1}{2} H_{2(g)} + \frac{1}{2} I_{2(g)}$?

Widal test is used for the diagnosis of