Company X provides bottled water to its employees in 5 liter bottles, $5 each. At least how many 5L bottles must Company X buy monthly, so that new contract with $40 fixed monthly rate and $2 for 20L bottle each paid off? (Assume that no other costs apply)
Choose the correct choice from the following answers:  A) 4  B) 9  C) 12  D) 20  E) 25
let the no. of 5 liter bottles be x, so the no. of 20l bottles will be x/4 (to equate the vol.) since the total cost will be equal , 5x= 40+2*x/4 so x= 8.88 or 9. Answer is (9).
<result>B</result>
Company X provides bottled water to its employees in 5 liter bottles, $5 each. At least how many 5L bottles must Company X buy monthly, so that new contract with $40 fixed monthly rate and $2 for 20L bottle each paid off? (Assume that no other costs apply)