What number will come in place of the question mark?
$$2:5::?:35$$

Let the unknown number in place of the question mark be $x$.The proportion is written as:
$$2:5=x:35$$
In fraction form:
$$\frac{2}{5}=\frac{x}{35}$$
Solving for $x$:
$$x=\frac{2}{5}\times 35$$
$$x=2\times 7=14$$