A cylindrical reservoir is $14 \mathrm{m}$ in diameter. Water is poured into it at the rate of $350 \mathrm{L}$ per minute. Find the rate in $\mathrm{cm}/\mathrm{hour}$ at which the water level rises in the reservoir.

Find the value of  $\frac{a}{b},$${\left(\frac{14}{9}\right)}^{-6}\times {\left(\frac{2}{7}\right)}^{-6}={\left(\frac{a}{b}\right)}^{-6}$

If $\mathrm{A}$ can do $\frac{1}{6}$ of a certain work in $4$ days and $\mathrm{B}$ can do $\frac{2}{3}$ of the work in $12$ days, then how long will $\mathrm{A}$ and $\mathrm{B}$ take to complete the work together?

Plot the points $\mathrm{P}(2,4), \mathrm{Q}(8,4), \mathrm{R}(10,1)$ and $\mathrm{S}(1,1)$ on a graph paper and join them by line segments. Do they lie on a straight line? If not, then name the type of geometrical figure formed by the line segments.

 In the given parallelogram $\mathrm{ABCD}$, $\mathrm{AC}$ and$\mathrm{BD}$are its diagonals intersecting at $\mathrm{O}$. If $\angle \mathrm{CAB}=25°,\angle \mathrm{CAD}=35°$ and $\angle \mathrm{COD}=110°,$ find  $\angle \mathrm{ODC}$.

In the given parallelogram $ABCD$, $AC$ and $BD$ are its diagonals intersecting at $\mathrm{O}$. If $\angle \mathrm{CAB}=25°,\angle \mathrm{CAD}=35°$,$\angle \mathrm{COD}=110°$ and $\angle \mathrm{DCB}=x°$, find the value of $x$.

Find solution to the following very long -answer type questions.

 In the given parallelogram $\mathrm{ABCD}$, $\mathrm{AC}$ and$\mathrm{BD}$are its diagonals intersecting at $\mathrm{O}$. If $\angle \mathrm{CAB}=25°,\angle \mathrm{CAD}=35°$ and $\angle \mathrm{COD}=110°,$ find  $\angle O\mathrm{BC}$.

Construct a quadrilateral$\mathrm{PQRS}$ in which $\mathrm{PQ}=5.5 \mathrm{cm},\mathrm{QR}=4.9 \mathrm{cm}, \mathrm{RS}=5.6 \mathrm{cm}$ $\mathrm{QS}=6 \mathrm{cm}$ and $\mathrm{SP}=4 \mathrm{cm}.$