If 5 men can build a house in 12 days, how many men are required to build the same house in 15 days? A cylindrical tin with base radius 28 cm and height 50 cm is filled with water. What is its capacit

The number of men and the number of days are inversely proportional. This means that the total work (men $\times$ days) is constant.
Let $M_1$ be the initial number of men and $D_1$ be the initial number of days.
Let $M_2$ be the new number of men and $D_2$ be the new number of days.
The formula is $M_1 D_1 = M_2 D_2$.

$M_1 = 5$ men, $D_1 = 12$ days.
$D_2 = 15$ days. We need to find $M_2$.

The number of men required is 4.

The formula for the volume of a cylinder is $V = \pi r^2 h$.
Given radius $r = 28 \text{ cm}$ and height $h = 50 \text{ cm}$. We will use $\pi = \frac{22}{7}$.

Given that $1000 \text{ cm}^3 = 1 \text{ litre}$.

The correct option is B. 123.2 litres.

An open tank has a bottom and four sides, but no top.
The dimensions are: length ($l$) = 10 m, width ($w$) = 5 m, height ($h$) = 3 m.

Area of the bottom = $l \times w = 10 \text{ m} \times 5 \text{ m} = 50 \text{ m}^2$.
Area of the two side faces = $2 \times (l \times h) = 2 \times (10 \text{ m} \times 3 \text{ m}) = 2 \times 30 \text{ m}^2 = 60 \text{ m}^2$.
Area of the two front/back faces = $2 \times (w \times h) = 2 \times (5 \text{ m} \times 3 \text{ m}) = 2 \times 15 \text{ m}^2 = 30 \text{ m}^2$.

The correct option is A. 140 m$^2$.

A cube is a three-dimensional solid object bounded by six square faces, with three meeting at each vertex. All edges are of equal length.

• Figure A is a circle.
• Figure B is a cylinder.
• Figure C is a triangular prism.
• Figure D is a cube. The correct option is D.

Two angles are supplementary if their sum is $180^\circ$.

Let the supplementary angle be $x$.

The correct option is B. $111^\circ$.