If a pair of linear equations is consistent,then the lines will be

Do the following equations represent a pair of coincident lines? Justify your answer.
$\frac{x}{2} + y + \frac{2}{5} = 0$
$4x + 8y + \frac{5}{16} = 0$

The present age of Ramesh is $x$ years. Mahesh is $5$ years elder than Ramesh and three years younger than Suresh. The present age of Suresh is $\ldots \ldots \ldots \ldots$

The pair of equations $2x + y - 4 = 0$ and $x + 2y - 5 = 0$ has........

Five years ago,the sum of the ages of a father and two sons was $x$ years. Then,after five years,the sum of the ages of all will be $\ldots \ldots \ldots$ years.

There are some $25$ paise coins and some $50$ paise coins in a bag. The total number of coins is $100$ and the total amount in the bag is Rs. $42.50$. Find the number of coins of each value in the bag.