Answer: There are 22 adults , 12 children and 11 senior citizens on the tour bus.
Step-by-step explanation:
Let adult = x
children = y
senior citizen = z
Given : Total busload (x+ y + z) = 45
Total charge on day 1 = 558 $ = [tex]15\times x+8\times y+12\times z[/tex]
Total charge on day 2 = 771 $ = [tex]20\times x+12\times y+17\times z[/tex]
Now we have 3 equations : x+ y+z =45
[tex]15\times x+8\times y+12\times z=558[/tex]
[tex]20\times x+12\times y+17\times z=771[/tex]
Solving for them we get: x= 22 , y = 12 and z= 11
Thus there are 22 adults , 12 children and 11 senior citizens.