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 the cost of an audio cassette be Rs x and that of a video cassette be. Rs y Then,

7x + 3y = 1110 ...(i)

5x + 4y = 1350 ...(ii)

Multiplying equation (i) by 4 and equation (ii) by 3, we get

28x + 12y = 4440 ...(iii)

15x + 12y = 4050 ...(iv)

Subtracting equation (iv) from equation (iii), we get

28x – 15x + 12y – 12y = 4440 – 4050

`=> 13x = 390`

`=> x = 390/13 = 30`

Substituting x = 30 in equation (i), w get

`7 xx 30 + 3y = 1110`

`=> 210 + 3y = 1110`

`=> 3y = 1110 - 210`

`=> 3y = 900`

`=> y = 900/3 = 300`

Hence, cost of one audio cassette = Rs 30 and cost of one video cassette = Rs 300.