Answer
$f\geq53$
At least 53 cans of food must be collected.
Work Step by Step
Let f equal the number of cans collected on Friday. To meet the goal of at least 160 cans, the team must collect 160 or more cans. To find the total number of cans, add the cans that will be collected on Friday to the 42 collected Monday and 65 collected Wednesday.
$f+42+65\geq160\longrightarrow$ combine like terms
$f+107\geq160\longrightarrow$ subtract 107 from each side
$f+107-107\geq160-107\longrightarrow$ subtract
$f\geq53$