20326

Question

Farmer Jim uses 5-strand wire fencing around his paddocks.

His fences have 3 barbed wire strands and 2 plain wire strands, as shown in the diagram below.



Barbed wire costs $b\text{\textdollar}\large b per metre. Plain wire costs $w\text{\textdollar}\large w per metre.

Which of these expressions gives the total cost of the wire needed for a fence of length ff metres?

Worked Solution

Cost of 3 metres of barbed wire = 3b3\large b

Cost of 2 metres of plain wire = 2w2\large w

⇒\rArr Cost of 1 metre of fencing = 3b3\large b + 2w\large w

∴\therefore Cost of ff metres of fencing

= {{{correctAnswer}}}

Variant 0

DifficultyLevel

574

Question

Farmer Jim uses 5-strand wire fencing around his paddocks.

His fences have 3 barbed wire strands and 2 plain wire strands, as shown in the diagram below.



Barbed wire costs $b\text{\textdollar}\large b per metre. Plain wire costs $w\text{\textdollar}\large w per metre.

Which of these expressions gives the total cost of the wire needed for a fence of length ff metres?

Worked Solution

Cost of 3 metres of barbed wire = 3b3\large b

Cost of 2 metres of plain wire = 2w2\large w

⇒\rArr Cost of 1 metre of fencing = 3b3\large b + 2w\large w

∴\therefore Cost of ff metres of fencing

= (3b(3\large b + 2w\large w)ff

Question Type

Multiple Choice (One Answer)

Variables

Variable nameVariable value
correctAnswer
$(3\large b$ + 2$\large w$)$f$

Answers

Is Correct?Answer
x

5bwf5\large b\large wf

x

6bwf6\large b \large wf

x

6(b+w6(\large b + \large w)ff

✓

(3b(3\large b + 2w\large w)ff