Die Naturlichen Pflanzenfamilien was written by

Assertion : Engler and Prantl proposed a natural Reason : Engler and Prantl system was published in ' Die Naturlichen Pflanzenfamilien'.

The mean of the numbers obtained on throwing a die having written 1 on two faces 2 on three faces and 4 on one face is....

The mean of the numbers obtained on throwing a die having written 1 on three faces, 2 on two faces and 5 on one face is

The mean of the numbers obtained on throwing a die having written 1 on three faces, 2 on two faces and 5 on one face is