My mother bought Xiaohong a coat and a pair of trousers in the shopping mall on Children's Day on June 1st, and spent 2 15 yuan, of which one coat 100 yuan and one pair of trousers got a 10% discount. What's the price of a pair of trousers?

2 15- 100*0.8= 135

135/0.9= 150

The price of a pair of trousers is 150 yuan.