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 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 = Rs30 and cost of one video cassette = Rs300