we know that
[tex]I=Prt[/tex]
where
I is the amount in interest
P is the investment
r is the interest rate
t is the time in years
Solve for t
[tex]t=I/(Pr)[/tex]
we have
[tex]I=\$1,400\\ P=\$27,000\\ r=4.2\%=0.042[/tex]
substitute
[tex]t=1,400/(27,000*0.042)=1.23\ years[/tex]
therefore
the answer is
[tex]1.23\ years[/tex]