F i = { 80 ( 2.5 − x ) f o r 0 ⩽ x < 2.5 64 ( x − 2.5 ) f o r 2.5 ⩽ x < 5.0 64 ( 7.5 − x ) f o r 5.0 ⩽ x < 7.5 28 ( x − 7.5 ) f o r 7.5 ⩽ x < 12.5 28 ( 17.5 − x ) f o r 12.5 ⩽ x < 17.5 32 ( x − 17.5 ) f o r 17.5 ⩽ x < 22.5 32 ( 27.5 − x ) f o r 22.5 ⩽ x < 27.5 80 ( x − 27.5 ) f o r 27.5 ⩽ x < 30 F_i = \begin{cases} 80(2.5-x) & for 0\leqslant x