The cost of a pen is 3 times the cost of a pencil and cost of a
notebook is 4 times that of a pen. If the cost of 6 pencils, 2
pens, and one notebook is $18, what is the cost of one pen?

1 Pen cost $2.25

Step-by-step explanation:

Assume:

Cost of Pen = a

Cost of pencil = b

Cost of notebook = c

a = 3b   (1)

c = 4a   (2)

2a + 6b + c = $18 (3)

From equation (1), b = a ÷ 3 (4)

Substitute equations (2) and (4) in equation (3)

2a + 6 * (a ÷ 3) + 4a = $18

2a + 2a + 4a = $18

8a = $18

a = $2.25

Therefore, 1 Pen cost $2.25

example 2 – simplify: step 1: completely factor both the numerators and denominators of all fractions. step 2: change the division sign to a multiplication sign and flip (or reciprocate) the fraction after the division sign; essential you need to multiply by the reciprocal. step 3 : cancel or reduce the fractions.