The cost of 1 knife is £5.52
Step-by-step explanation:
The given is:
- A knife is three times the cost of a spoon
- 9 spoons and 12 knives cost £82.80
We need to find the cost of 1 knife
Assume that the cost of one spoon is x and the cost of one knife is y
∵ The cost of one spoon = x
∵ The cost of one knife = y
∵ The cost of a knife is three times the cost of a spoon
-That means y is 3 times x
∴ y = 3 x ⇒ (1)
∵ 9 spoons and 12 knives cost £82.80
∴ 9 x + 12 y = 82.80 ⇒ (2)
Now we have a system of equations to solve it
Substitute y in equation (2) by equation (1)
∴ 9 x + 12(3 x) = 82.80
∴ 9 x + 36 x = 82.80
- Add the like terms in the left hand side
∴ 45 x = 82.80
- Divide both sides by 45
∴ x = 1.84
- Substitute the value of x in equation (10 to find y
∵ y = 3(1.84)
∴ y = 5.52
The cost of 1 knife is £5.52
Learn more:
You can learn more about the system of equations in brainly.com/question/3739260
#LearnwithBrainly
