A diver of Residual Group E at the time of the first diving end plans the second diving of 35 minutes at 15 m after 1 hour 30 minutes Surface Interval Time.Which is Residual Group?

《The usage of Dive Table》

Residual Nitrogen Time for the second diving of 15 m deep is 13 minutes in <Table 3> No-decompression Dive Limit- Residual Nitrogen Time Table.
The second diving is 35 minutes at 15m in real Bottom Time.
Residual Nitrogen Time　13 minutes　＋　The second Bottom Time 35 minutes　＝　Calculated new bottom time 48 minutes.

The Bottom Time of the second diving should be regard as 48 minutes.You can examine Residual Group by using 48 minutes in <Table 1> Bottom Time – Residual Group Table.

Correct answer： F

The Residual Group at the time of the second diving end is F.

*A Dive Table term*

■Calculated new bottom time
　This is the time that is equal to the total of Bottom Time and Residual Nitrogen Time.
　As you should take Residual Nitrogen Time into consideration, this time is used to plan the next diving