A salesman gets a basic wage of £160 per week plus a commision of 30% of the sales he makes that week. In one week his total wage was £640 Work out the value of the sales he made that week.

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?