Question

Sol. [Key Concept: Ploidy of gametophytic tissues from 2n]

The endosperm is triploid, if the diploid chromosome number of typical angiosperm is 36

$$\begin{matrix} & \text{~}\text{i.e.}\text{~}\begin{matrix} 2n & \ = 36\text{~}\text{then}\text{~}n = 18 \\ \text{~}\text{So,}\text{~}3n & \ = n + n + n \\ & \ = 18 + 18 + 18 \\ & \ = 54 \end{matrix} \end{matrix}$$