When a point (x,y) rotated 180⁰ about origin, the new point will be (-x, -y).
So,
if we have (5, -1), it should become (-5, 1).
So,
answer is true.
Let the number of boys and the number of girls be 5x and 4x
Number of girls = 4x = 60
x = 15
Number of boys = 5x
= 5× 15
= 75 boys
It's a bit tedious, but it's just a bunch of factoring and manipulation.
Its like that because the judges deduct points from that score. They can be major or minor deductions.