The solution of the pair of equations $x + 2y = 5$ and $2x + y = 4$ is .........

Find the value of $k$ under the given condition for the following pair of linear equations: $2x - 3y = 1$ and $kx + 5y = 7$,such that the system has a unique solution.

$A$ boat goes $32 \, km$ upstream and $36 \, km$ downstream in $7$ hours. In $9$ hours,it can go $40 \, km$ upstream and $48 \, km$ downstream. Determine the speed of the stream and that of the boat in still water. (Speed of boat in still water is more than the speed of the stream of river.)

The total cost of three tables and two chairs is ₹ $3400$. The cost of two tables and three chairs is ₹ $3100$. Then the total cost of a chair and a table is ₹ ...............

$A$ number is $3$ less than another number. By adding $17$ to twice the larger number,it becomes thrice the smaller number. Find these numbers.

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 $\ldots \ldots \ldots \ldots$