Question

The cost of 2k articles is ` (54 + 5k) while the cost of (k + 2) articles is ` (10k – 4). We need to find k.

Answer 1

♧♧HERE IS YOUR ANSWER♧♧

Given :

The cost of 2k articles = Rs (54k + 5k)

So, the cost of 1 article = Rs (54k + 5k)/2k


Also, the cost of (k + 2) articles = Rs (10k - 4)

So, the cost of 1 article = Rs (10k - 4)/(k + 2)


Hence,

(54k + 5k)/2k = (10k - 4)/(k + 2)

By cross multiplication, we get :

54k + 5k² + 108 + 10k = 20k² - 8k

⇒ 15k² - 72k - 108 = 0

⇒ 5k² - 24k - 36 = 0

⇒ 5k² - 30k + 6k - 36 = 0

⇒ 5k(k - 6) + 6(k - 6) = 0

⇒ (k - 6)(5k + 6) = 0

Either k - 6 = 0 or, 5k + 6 = 0

⇒ k = 6 or, k = -6/5

Since k is number of articles, k = 6, k ≠ -6/5.

Therefore, k = 6.

♧♧HOPE THIS HELPS YOU♧♧

Answer 2

thank you for your answer