There are 5 pipes, such as A, B, C, D, and E, and each pipe can fill the tank in 10 minutes. If the efficiency of pipes B, C, and E increased to 2 times, 2 times, and x times, respectively, then the tank will be filled in 1 minute. Find the value of x.
1
5
2
6
3
4
4
3
5
2