Question

Donna sells pencils for $2 and pens $3. She sold 11 items and made $30. How many pens did she sell ?

Answer 1

Donna sold 3 pencils and 8 pens solved using simultaneous equation

What is a simultaneous equation?

Simultaneous equation refers to related equations that are solved at the same to derive answers to the unknown variables

Let assume that X pencils were sold and Y pens were sold

The total revenue is the sum of the prices multiplied by the quantities sold.

2X+3Y=30   (equation 1)

The sum of X and Y sold is 11

X+Y=11   (equation 2)

multiply the second equation by 2

2*(X+Y=11)

2X+2Y=22 (equation 3)

subtract equation 3 from 1

(2X+3Y=30)-(2X+2Y=22)

Y=8

Substitute for Y in equation 2

X+8=11

X=11-8

X=3

Which means he sold 3 pencils and 8 pens.

Find details on simultaneous equation in the link below:

brainly.com/question/20627346

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