Alan invests a total of $16,000 in three different ways. He invests one part in a mutual fund which in the first year has a return of 11%. He invests the second part in a government bond at 7% per year. The third part he puts in the bank at 5% per year. He invests twice as much in the mutual fund as in the bank. The first year Alan's investments bring a total return of $1360. How much did he invest in each way?