Ethyl acetate reacts with $CH_3MgBr$ to form

Identify $A$ in the following reaction: $A + CH_3MgBr$ $\xrightarrow{\text{ether}} \text{complex}$ $\xrightarrow{H_3O^{+}} (CH_3)_3C-OH$

Consider the following reactions. Total number of electrons in the $\pi$ bonds and lone pair of electrons in the product is:

Consider the following reactions:
$A$ $\xrightarrow[(i) CH_3MgBr]{(ii) H_3O^{+}} B$ $\xrightarrow[573 \text{ K}]{Cu} 2\text{-methyl-2-butene}$
The mass percentage of carbon in $A$ is:

Metaformaldehyde is:

$C_{7}H_{10}O$ reacts with $CH_{3}MgBr$ to give a compound $C_{8}H_{12}O$ which gives a positive iodoform test. Identify the structure of $A$.