Question

$7$ audio cassettes and $3$ video cassettes cost Rs. $1110$, while $5$ audio cassettes and $4$ video cassettes cost Rs. $1350$. Find the cost of an audio cassette and a video cassette.

Answer 1

Let cost of audio cassette =$x$

And cost of video cassette =$y$

$\Rightarrow 7x+3y=1110$

$\Rightarrow 5x+4y=1350$

Equation (1) × 4 : $28x+12y=1110\times 4$

Equation (2) × 3 : $15x+12y=1350\times 3$

Subtract two equations ;

$\Rightarrow 13x=390$

$\Rightarrow x=30$

Substituting in above equations, we get ;

$\Rightarrow y=300$