Aknife is twice the cost of a spoon. 8 spoons and 12 knives cost ? 46.08. work out the cost of 1 knife.

Let Rs.x and Rs.y be the cost of a knife and a spoon respectively.
From question,
x = 2y --- (1)
and,
12x + 8y = 46.08
=> 12×2y + 8y = 46.08
=> 24y + 8y = 46.08
=> 32y = 46.08
=> y = 46.08/32
=> y = 1.44
putting y = 1.44 in (1)
=> x = 2×1.44
=> x = 2.88
Therefore, cost of a knife is Rs 2.88