To answer this item, we let x be the amount of money he has left that was initially part of the total $450.
First, subtract $210 from it (spent by Adam on food)
$450 - $210 = $240
Then, divide the remaining amount of money by 4
$240 / 4 = $60
Since, it was only one part that he kept to himself, the amount of money left with him, x, is
x = $60
Then, the total amount of money he has including that which he only picked from the road is,
T = $60 + $50 = $110
In the end, Adam had $110.