Question 952717
Let x be the number of 13kg panels and y be the number of 22kg panels, then
x + y = 65
(x*13) + (y*22) = 1205
solve for x in first equation
x = 65 - y
(65-y)*13 + (y*22) = 1205
845 -13y + 22y = 1205
9y = 360
y = 40 and
x = 25
therefore
there are 25 13kg panels and 40 22kg panels