The common region of the solution of the inequations $x+y \geq 5$,$y \leq 4$,$x \geq 2$,$x, y \geq 0$ is

In drilling the world's deepest hole,it was found that the temperature $T$ in degrees Celsius,$x \text{ km}$ below the earth's surface,is given by $T = 30 + 25(x - 3)$,where $3 \leq x \leq 15$. At what depth will the temperature be between $155^{\circ}C$ and $205^{\circ}C$?

For a positive integer $n$,if $10^{n-2} > 91n$,then the complete set of values of $n$ is:

$A$ triangle is formed by the $X$-axis,$Y$-axis,and the line $3x + 4y = 60$. The number of points $P(a, b)$ which lie strictly inside the triangle,where $a$ is an integer and $b$ is a multiple of $a$,is $...........$

$A$ solution is to be kept between $86^{\circ} F$ and $95^{\circ} F$. What is the range of temperature in degree Celsius if the Celsius $(C)$/Fahrenheit $(F)$ conversion formula is given by $F = \frac{9}{5} C + 32$?

$A$ solution of $8 \%$ boric acid is to be diluted by adding a $2 \%$ boric acid solution to it. The resulting mixture is to be more than $4 \%$ but less than $6 \%$ boric acid. If we have $640$ litres of the $8 \%$ solution,how many litres of the $2 \%$ solution will have to be added?