The simple rule is that 15° correspond 1 hour difference. To the west of a prime meridian, time zones decrease, to the east time increases.
So, we have 60°+40°=100° degrees difference. In hours it will be
Now, to find time at 40° E, all we need to do is to add 6 h 40 min to 7:30, which results in
Thus, for 40°E, the time will be 2:10 pm.