The task is to generate the correct answer for a given math problem.

Problem: the average of 6 no . ' s is 3.95 . the average of 2 of them is 3.8 , while the average of theother 2 is 3.85 . what is the average of the remaining 2 no ' s ?
4.2

Problem: the number of singles that a baseball player hit increased 10 percent from her first season to her second season , and the number of doubles that she hit in the same time period decreased by 1 percent . if the total number of singles and doubles that she hit increased 3 percent from her first season to her second season , what is the ratio of the number of singles she hit in her first season to the number of doubles she hit in her first season ?
4 : 7

Problem: a number is increased by 20 % and then decreased by 20 % . find the net increase or decrease per cent .

4 

