Taro and Jiro respectively decided to make a plan to do homework of the mathematics in the summer vacation.
Taro decided to solve three problems a day from the first day of the summer vacation. Jiro decided not do its homework for six days of the beginning of the summer vacation and from seventh day to solve [ ] problems a day until he finish the homework.
It was found that several days after Jiro started to solve, the number of problems solved by Taro and Jiro are the same. Since the day above Taro solved five problems a day until the day he would finish, but it was two days after the day Jiro finished.
The number of days that Taro solved three problems a day is same as the number of days Taro solved five days a day.
Answer the following questions.
(1) How many days did Taro take to finish the homework?
(2) How many days did Jiro take to finish the homework?
(3) Find the number applied in [ ].