Given :
Volume of water in a transfer pipette is 15.23 ml.
A 6.7 ml volume of water was then transferred out.
To Find :
The new volume.
Solution :
Initial volume ,
.
Volume removed out , v = 6.7 ml .
Let, new volume be
.
Now , new volume = Initial volume - Volume removed out .

Therefore, new volume is 8.5 ml.
Hence, this is the required solution.