Answer:
Ok, so I don't know what language you want this in, so I will do C++ as it is easiest for me. Also, I may use the wrong syntax for print etc, and the comparison syntax may not be accurate, but if you know what you are doing you should be able to see how it works.
int s;
print("enter your score");
s=input;
if(s>==90){
print("A");
}
if((s>==80)&&(s<90)){
print("B");
}
if((s>==70)&&(s<80)){
print("C");
}
if((s>==60)&&(s<70)){
print("D");
}
if(s<60){
print("E");
}
Step-by-step explanation: