Given that : $\triangle \mathrm{ABC} \sim \Delta \mathrm{PQR}$, If $\frac{\text { area }(\Delta \mathrm{PQR})}{\text { area }(\Delta \mathrm{ABC})}$ $=\frac{256}{441}$ and $\mathrm{PR}=12 \mathrm{~cm}$, then $\mathrm{AC}$ is equal to

If the perimeter of a rhombus is 40 cm and one of its diagonals is 16 cm, what is the area (in cm2) of the rhombus?

The simplified value of :

$\left\{\begin{array}{l}\left(1+\frac{1}{10+\frac{1}{10}}\right)\left(1+\frac{1}{10+\frac{1}{10}}\right) \\ \left(1-\frac{1}{10+\frac{1}{10}}\right)\left(1-\frac{1}{10+\frac{1}{10}}\right)\end{array}\right\} \div\left\{\left(\begin{array}{l}\left.\left.1+\frac{1}{10+\frac{1}{10}}\right)\left(1-\frac{1}{10+\frac{1}{10}}\right)\right\}\end{array}\right\}\right.$

Two pipes A and B can fill a tank with water in 30 minutes and 45 minutes respectively. The water pipe C can empty the tank in 36 minutes. First A and B are opened. After 12 minutes C is opened. Total time (in minutes) in which the tank will be filled up is :

If the angle between two lines is $\frac{\pi}{4}$ and the slope of one of the lines is $\frac{1}{2}$, then the slope of other line will be

If $P=\frac{(\sqrt{7}-\sqrt{6})}{(\sqrt{7}+\sqrt{6})}$, then what is the value of $\left(\mathrm{P}+\frac{1}{\mathrm{P}}\right) ?$

The number of boys using Whatsapp in February is how much per cent more than the number of boys using Facebook in February?

What is the total number of boys using the three apps in the month of March?

The number of boys using Whatsapp in March is what per cent of the number of boys using Facebook in February?

What is the percentage decrease in the number of boys using Facebook from January to February?