The major product $(P)$ of the given reaction is .... (where,$Me$ is $-CH_3$)

$CH_3-CH(OH)-CH_3$ $\xrightarrow{PBr_3} X$ $\xrightarrow{Mg/\text{ether}} Y$ $\xrightarrow{H_2O/H^+} \text{The final product is}$

Product $W$ is

Which of the following compounds are not oxidized by $HIO_4$?
$(1)$ $CH_3-CH(OH)-CH_2-OH$
$(2)$ $CH_3-C(=O)-CHO$
$(3)$ $CH_3-C(=O)-C(=O)-CH_3$
$(4)$ $CH_3-C(=O)-CH(NH_2)-CH_3$
$(5)$ Cyclohexene oxide
$(6)$ $CH_3-O-CH_2-CH_2-OH$
$(7)$ $HOOC-CH_2-OH$

An organic compound $X$ is oxidised by using acidified $K_{2}Cr_{2}O_{7}$. The product obtained reacts with phenyl hydrazine but does not answer the silver mirror test. The possible structure of $X$ is

What is the $IUPAC$ name of the organic compound formed in the following chemical reaction?
Acetone $\xrightarrow[(ii) H_2O, H^{+}]{(i) C_2H_5MgBr, \text{dry Ether}}$ Product