Final grades calculator

The score is calculated by:There will be two midterms (15% each), a comprehensive final exam (30%), homework (25%), quizzes (15%). Final semester grades are assigned according to the scale:

93 - 100% A	90 - 92% A-	87 - 89% B+
83 - 86% B	80 - 82% B-	77 - 79% C+
70 - 76% C	60 - 69% D	0 - 59% F


# Drop the lowest homework and quiz
# No curving.

HW <- c(100,80,50)
HW <- sort(HW)[-1]                  # drop the lowest homework

QZ<- c(79,99,100,90)
QZ <- sort(QZ)[-(1:3)]                  # drop the lowest 3 quizzes 

Mid1 <- 98
Mid2 <- 95
Final <- 75

T_Num_HW <- 14                      # total number of hw I assign, not the number you hand in.
T_Num_QZ <- 13                      # total number of quiz I assign, not the number you take

Num_HW <- T_Num_HW - 1              # since we drop 1
Num_QZ <-  T_Num_QZ - 1             # since we drop 1

YourScore <- 0.25* sum(HW)/Num_HW + 0.15*sum(QZ)/Num_QZ + 0.15*Mid1 + 0.15*Mid2 + 0.3*Final

YourScore <- ceiling(YourScore)     # I will round up!

LetterGrade <- NULL

if (YourScore >= 93){
   LetterGrade <- "A"
} else if(YourScore >= 90){
     LetterGrade <- "A-"
} else if (YourScore >= 87){
     LetterGrade <- "B+"
} else if (YourScore >= 83){
     LetterGrade <- "B"
} else if (YourScore >= 80){
     LetterGrade <- "B-"
} else if (YourScore >= 77){
     LetterGrade <- "C+"
} else if (YourScore >= 70){
     LetterGrade <- "C"
} else if (YourScore >= 60){
     LetterGrade <- "D"
} else{
      LetterGrade <- "F"
}

cat("Your Score = ", YourScore , "\n")
cat("Hence your final letter Score = ",LetterGrade, "\n")