PSAT has 3 sections:
math: 得分范围 8 - 38
reading: 8 - 38
writing&language: 8 - 38
example:
math: 37.5
reading: 36
writing&language:37
PSAT total score:
(reading + writing&language) * 10 + math * 20 = (36 + 37) * 10 + 37.5 * 20 = 1480
index score: (reading + writing&language + math) * 2 = (36 + 37 + 37.5) * 2 = 221
max score: (38 + 38) * 10 + 38 * 20 = 760 + 760 = 1520
max index: (38 + 38 + 38) * 2 = 228