Answer:
$7
Explanation:
In order to find the total cost of the 3 beakers, take away $6 from the total amount Adam has.
$27 - $6 = $21
$21 is the amount needed for 3 beakers, hence to find 1 beaker, you just have to divide $21 by 3.
$21 ÷ 3 = $7
Therefore, each beaker costs $7.