70041

Question

A small patio required 16 slabs to cover it. The cost of using 12 colored slabs and 4 white ones is $68. If 8 colored slabs and 8 white ones are used instead, the cost becomes $56.

Find the cost of the arrangement below which uses 4 colored slabs and 12 white ones.

Worked Solution

Let C = cost of a coloured slab and let W = cost of a white slab, then
12C + 4W = 68 ... (1)
8C + 8W = 56 ... (2)

Multiply (1) ×\times 2
24C + 8W = 136 ... (3)

Subtract (3) - (2)
16C = 80
C = 5

Substitute C = 5 into (2)
8 ×\times 5 + 8W = 56
8W = 16
W = 2

⇒\rArr C costs $5 and W costs $2
∴\therefore Cost of new arrangement = 4C + 12W
= 4 ×\times 5 + 12 ×\times 2
= {{{correctAnswer}}}

Variant 0

DifficultyLevel

720

Question

A small patio required 16 slabs to cover it. The cost of using 12 colored slabs and 4 white ones is $68. If 8 colored slabs and 8 white ones are used instead, the cost becomes $56.

Find the cost of the arrangement below which uses 4 colored slabs and 12 white ones.

Worked Solution

Let C = cost of a coloured slab and let W = cost of a white slab, then
12C + 4W = 68 ... (1)
8C + 8W = 56 ... (2)

Multiply (1) ×\times 2
24C + 8W = 136 ... (3)

Subtract (3) - (2)
16C = 80
C = 5

Substitute C = 5 into (2)
8 ×\times 5 + 8W = 56
8W = 16
W = 2

⇒\rArr C costs $5 and W costs $2
∴\therefore Cost of new arrangement = 4C + 12W
= 4 ×\times 5 + 12 ×\times 2
= $44

Question Type

Multiple Choice (One Answer)

Variables

Variable nameVariable value
correctAnswer
$44

Answers

Is Correct?Answer
x

$34

x

$38

x

$40

✓

$44

Tags

  • staging_suejones