Answer
The area of the solar collector is $41.7~m^2$
Work Step by Step
Let $A$ be the area of the solar collector. The total energy collected by the solar collector is the intensity multiplied by the area multiplied by the time. Therefore;
$I~A~t = E$
$A = \frac{E}{I~t}$
$A = \frac{150\times 10^6~J}{(1000~W/m^2)(3600~s)}$
$A = 41.7~m^2$
The area of the solar collector is $41.7~m^2$.