A yearly bus pass is 157.50 dollars after a 12.5% discount. Estimate the original as between 175 and 185 dollars, then choose the exact original price.

Explication

The sale price is 87.5% of the original, so 157.50 × 100 / 87.5 = 180. Adding 12.5% of 157.50 gives 177.19, which is close but uses the discounted price as the wrong base.