Two years ago,Salim was thrice as old as his daughter and six years later,he will be four years older than twice her age. How old are they now? (in $year$)

Solve the following pairs of linear equations: $\frac{5}{a} - \frac{6}{b} = 3$ and $\frac{1}{a} + \frac{4}{b} = 11$.

Vijay had some bananas,and he divided them into two lots $A$ and $B$. He sold the first lot at the rate of $Rs. 2$ for $3$ bananas and the second lot at the rate of $Rs. 1$ per banana,and got a total of $Rs. 400$. If he had sold the first lot at the rate of $Rs. 1$ per banana,and the second lot at the rate of $Rs. 4$ for $5$ bananas,his total collection would have been $Rs. 460$. Find the total number of bananas he had.

The age of the father is twice the sum of the ages of his two children. After $20$ years,his age will be equal to the sum of the ages of his children. Find the age of the father (in years).

$A$ fraction becomes $\frac{4}{5}$ if $1$ is added to both the numerator and the denominator. If $5$ is subtracted from both the numerator and the denominator,it becomes $\frac{1}{2}$. Find the fraction.

Solve the following pair of linear equations by the method of elimination: $0.3 x + 0.4 y = 1$ and $6 x + 8 y = 20$.