Question

An oculist charges $40 for an eye examination, frames
and glass lenses, but $52 for an eye examination,
frames and plastic lenses. If the plastic lenses cost
four times as much as the glass lenses, how much do
the glass lenses cost?
(a) $3
(b) $4 w (c) $5
(d) $6
(e) $12​

Answer 1

Answer:

(b) $4

Step by step explanation:

Think,

Eye examination = a,

Frames = b

Glass lenses = x

Plastic lenses = y

Now,

a + b + y = 52 ----( i )

a + b + x = 40 ----( ii )

y = 4x ----( iii )

( i ) - ( ii )

= (a + b + y) - (a + b + x)

(a + b + y) - (a + b + x) = 52 - 40

or, a + b + y - a - b - x = 12

or, y - x = 12

or, 4x - x = 12 [Using ( iii )]

or, 3x = 12

or, x = 12÷3

or,x = 4

x= 4

So , x or glass lenses cost $4

That's it Folks