Which of the following is a reducing sugar?

Which of the following compounds does not contain a peroxide ion?

In a $U$-tube experiment,a column $AB$ of water is balanced by a column $CD$ of oil,as shown in the figure. Then the relative density of oil is

Two friends $A$ and $B$ are $30 \, km$ apart and they start simultaneously on motorcycles to meet each other. The speed of $A$ is $3$ times that of $B$. The distance between them decreases at the rate of $2 \, km$ per minute. Ten minutes after they start,$A$'s vehicle breaks down and $A$ stops and waits for $B$ to arrive. After how much time (in minutes) since $A$ started riding,does $B$ meet $A$?

$A$ coin and a six-faced die,both unbiased,are thrown simultaneously. The probability of getting a head on the coin and an odd number on the die is:

If $f(t) = \int_{-t}^t \frac{e^{-|x|}}{2} dx$,then $\lim_{t \rightarrow \infty} f(t)$ is equal to: