What is the S.I. unit of mass? Write it's name and symbol. 

Convert the following quantities as indicated :

$12 \mathrm{inch} =$_____  $\mathrm{ft}$.

Convert the following quantities as indicated : 

$1 \mathrm{ft}=$_____  $\mathrm{cm}$.

Convert the following quantities as indicated : 

$20 \mathrm{cm}=$_____  $\mathrm{m}$.

Convert the following quantities as indicated : 

$4.2 \mathrm{m} =$ _____  $\mathrm{cm}$.