Joe has twice as many cars as Robert. He sells 20% of them and gives away twice as many cars as the number he sold to his mother. If Robert has 20 cars, how many cars does joe remain with after selling and giving some to his mother?
If Robert has 20 cars, and Joe has twice as many cars as Robert, Joe has 2*20 = 40 cars.
He then sells 20/100*40=<<20/100*40=8>>8 cars from his car collection.
After selling 8 cars, Joe remains with 40-8=<<40-8=32>>32 cars.
Joe then gives away twice as many cars as the number he sold to his mother, a total of 2*8=<<2*8=16>>16 cars.
The number of cars that Joe has remaining after giving 16 cars to his mother is 32-16=<<32-16=16>>16
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