bayside insurance offers two health plans. Under plan "A" Giselle would have to pay the first $90 of her medical bills plus 25% of the rest. Under plan "B"Giselle would pay the first $190 but only 20% of the rest. For what amount of medical bills will plan "B" save Giselle money? Assume that she has over $190 in bills..

Set the Plan A and Plan B contributions costs equal and solve for the required billing, X.

90 + 0.25(X-90) = 190 + 0.20(X-190)

100 = 0.05X -22.5 + 38

0.05X = 84.5
X = $ 1690.

Plan B is better if billings exceed $1690. That is presumably per calendar year.