70040

Question

A small patio required 16 slabs to cover it. The cost of using 4 colored slabs and 12 blank ones is $20. If 8 colored slabs and 8 blank ones are used instead, the cost becomes $24.

Find the cost of this arrangement which is made up by using 2 colored slabs and 10 blank ones.

Worked Solution

Let C = cost of coloured slab

Let B = cost of blank slab
4C + 12B = 20 ... (1)
8C + 8B = 24 ... (2)

Multiply (1) ×\times 2

8C + 24B = 40 ... (3)

Subtract (3) - (2)
16B = 16
B = 1

⇒\rArr C costs $1 and B costs $2
∴\therefore Cost = 14B + 2C
= 14 ×\times 1 + 2 ×\times 2
= {{{correctAnswer}}}

Variant 0

DifficultyLevel

100

Question

A small patio required 16 slabs to cover it. The cost of using 4 colored slabs and 12 blank ones is $20. If 8 colored slabs and 8 blank ones are used instead, the cost becomes $24.

Find the cost of this arrangement which is made up by using 2 colored slabs and 10 blank ones.

Worked Solution

Let C = cost of coloured slab

Let B = cost of blank slab
4C + 12B = 20 ... (1)
8C + 8B = 24 ... (2)

Multiply (1) ×\times 2

8C + 24B = 40 ... (3)

Subtract (3) - (2)
16B = 16
B = 1

⇒\rArr C costs $1 and B costs $2
∴\therefore Cost = 14B + 2C
= 14 ×\times 1 + 2 ×\times 2
= $18

Question Type

Multiple Choice (One Answer)

Variables

Variable nameVariable value
correctAnswer
$18

Answers

Is Correct?Answer
x

$16

✓

$18

x

$20

x

$22

Tags

  • wf_draft