$A$ circular swimming pool is surrounded by a concrete wall $4 \ m$ wide. If the area of the concrete wall surrounding the pool is $11/25$ that of the pool,then the radius (in $m$) of the pool is

An isosceles right-angled triangle has an area of $200 \, cm^2$. The length of its hypotenuse is ..... $cm$.

The radius and vertical height of a cone are $5 \text{ cm}$ and $12 \text{ cm}$ respectively. Then its lateral surface area is? (in $\text{cm}^2$)

$A$ room $5\, m \times 8\, m$ is to be carpeted leaving a margin of $10\, cm$ from each wall. If the cost of the carpet is ₹ $18$ per $m^2$,then the cost of carpeting the room will be (in $Rs.$)

Wheels of diameters $7\, cm$ and $14\, cm$ start rolling simultaneously from $X$ and $Y$,which are $1980\, cm$ apart,towards each other in opposite directions. Both of them make the same number of revolutions per second. If both of them meet after $10\, seconds$,the speed of the smaller wheel is.........$cm/sec$.

If the diagonal of a square is doubled to make another square,the area of the new square will