Can anyone answer this math problem?

Question

An oculist charges $30 for an eye examination, frames, and glass lenses, but $42 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?

Answer 1

$4 I think.

Answer 2

not enough information you need to know the cost of 1 item

Answer 3

3$ b/c 3X4 is 12..... 30 + 12 = 42

Answer 4

$16

Exam + Frames = $26

Glass lenses cost $4

Plastic lenses cost 4 x $4 = 16

$26 + $16 = $42

Answer 5

42-30 is 12$ for the plastic and if that is four times as much as the glass it is 3$ for the glass lenses

Answer 6

let e = cost of exam, f = cost of frame, g = cost of glass lense, p = cost of plastic lense

30 = e + f + g

rearrange so that

e + f = 30 - g

42 = e + f + p

and p = 4g

42 = e + f + 4g

rearrange so that

e + f = 42 - 4g

42 - 4g = 30 - g

12 = 3g

g = 4

glass lenses cost $4

Answer 7

16

Answer 8

3

Answer 9

how much for the glass lenses ?

Answer 10

Easy peasy $28

Answer 11

like 6 bux

$6