The bike store marks up the wholesale cost of all of the bikes they sell by 30%. Andre wants to buy a bike that has a price tag of $125. The wholesale cost of this bike was $87.50.

Suppose that the wholesale of a bike is A (A is the 100% in this case). If we have an increase of 30% for the sale price, we have the new price of:

Price = A + (30%/100%)A = A + 0.3*A = (1.3)*A

Then if we know that the price tag of the bike is $125, then we have:

$125 = (1.3)*A

$125/1.3 = A = $96.15

The wholesale cost of the bike is $96.15