Solution:
Given:

The volume of a sphere is given by;

Hence, the volume of the truffles will be;
Reflection, the quadratic parent function is reflected on the opposite side
let 'x' represent the number of all the passes for the year
350 passes = 70% of all the passes
350 passes = 70% of x
0.70x = 350
by solving we find:
x = 500 passes
It would be 62 hope this helps