The original price of a ski jacket was $210. It was on sale at a 25% discount. Arianna had a coupon for an additional 10% off the sale price. What price did Arianna pay for the ski jacket?
The sale price of the jacket was $210 - $210 x 0.25 = $210 - $52.50 = $<<210-210*0.25=157.5>>157.50
Arianna's coupon gave her an additional discount of $157.50 x 0.10 = $15.75
The price Arianna paid for the jacket was $157.50 - $15.75 = $<<157.5-15.75=141.75>>141.75. Answer: \boxed{141.75}.