Soft drinks cost $1.89 and refills cost $0.25 each. with $3.80 to spend on the soft drink and refills, what is the maximum number of refills that you can get?

The maximum number of refills that you can get is 7.

Solution:
3.80=1.89+0.25x
x=1.91/0.25=7.64=7(We take it as 7 because,if we need 8 cups we will jave to pay more,I think there is not such a subject of rounding decimal in sale)