$SiC{l}_4\stackrel{H_{2}O}{\to }X\stackrel{1000}{\to }Y$
In the above reaction, how many oxygen atom(s) is/are present in X and Y ?
[If answer is 6 and 4, represent as 64]

$SiC{l}_4\stackrel{H_{2}O}{\to }\underset{X}{Si(OH{)}_4}\stackrel{1000}{\to }\underset{Y}{Si{O}_2}$
In the above reaction, four oxygen atoms are present in X and two oxygen atoms are present in Y. Hence, the answer is 42.