Question

A pen and a ruler cost $2.10. 2 such pens and 3 such rulers cost $4.90. Find the cost of one ruler.

Answer 1

The cost of one ruler is $0.70

Applications of simultaneous equations

From the question, we are to determine the cost of one ruler

Let x represent the cost of a ruler

and

y represent the cost of a pen

From the given information, we can write that

y + x = $2.10 ----------- (1)

2y + 3x = $4.90  ----- (2)

From equation (1),

y + x = $2.10

Then,

y = $2.10 - x

Substitute this into equation (2)

2y + 3x = $4.90

2($2.10 - x) + 3x = $4.90

$4.20 - 2x + 3x = $4.90

$4.20 +x = $4.90

x = $4.90 - $4.20

x = $0.70

Hence, the cost of one ruler is $0.70

Learn more on Simultaneous equations here: brainly.com/question/26310043

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