A chemical company makes two brands of antifreeze. The first brand is 60% pure antifreeze, and the second brand is 85% pure antifreeze. In order to obtain 170 gallons of a mixture that contains 65% pure antifreeze, how many gallons of each brand of antifreeze must be used?

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?