How many carbonyl compounds will give secondary alcohol with molecular formula ${\mathrm{C}}_5{\mathrm{H}}_{12}\mathrm{O}$ after reduction with ${\mathrm{LiAlH}}_4$? 

$\mathrm{X}$ (an ethyl ester) $\underset{\left(\mathrm{ii}\right) {\mathrm{H}}_3{\mathrm{O}}^{\oplus }}{\overset{\left(\mathrm{i}\right) \mathrm{Grignard}\text{'}\mathrm{s} \mathrm{reagent} \left(\mathrm{Y}\right) \left(\mathrm{execess}\right)}{\to }}$ Product  

The product(s) may be:

True statement about above reaction:

The product is:

Observe the following reaction sequence:

Calculate the molecular mass $\mathrm{W}$ of the product $\mathrm{I}$ and report your answer as $\mathrm{N}$, where $\mathrm{N} =\mathrm{W}÷3$