A blue dress costs two times as much as a red dress. A yellow dress costs $ $2.40$ more than a blue dress. Hailey bought a blue dress, a red dress and a yellow dress. She spent $ $65.40$ in total. How much does a blue dress cost? 
Overseas Competition->Knowledge Point->Calculation Modules->Decimals->Addition and Subtraction of Decimals Overseas Competition->Knowledge Point->Word Problem Modules->Applying Addition and Subtraction->Simple Addition and Subtraction