# your code goes here
#exam $in$ filter(class ==1 )
# 필터 filter ( 조건 class ==1 , english >= 90)
# 1반 클래스에서 90점 이상인 사람
# |(class %in% )
# %/% 나눗셈의 몫 %%나머지
# exam %>% filter(class == 1)
exam <- c(1:20)
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