How can I use "IF" & "AND" in Excel

How can solve the following in Excel??? if mark is 136-150   grade is 10                121-135   grade is 9                106-120...

How can solve the following in Excel???

if mark is 136-150   grade is 10
               121-135   grade is 9
               106-120   grade is 8
                 91-105   grade is 7
                 83-90    grade is 6
                 75-82    grade is 5.5
                 else        grade is  0



you can use this formula for solving the above in excel...

=IF(AND(B3<=150,B3>=136),10,IF(AND(B3<=135,B3>=121),9,
IF(AND(B3<=120,B3>=106),8,IF(AND(B3<=105,B3>=91),7,
IF(AND(B3<=90,B3>=83),6,IF(AND(B3<=82,B3>=75),5.5,0))))))

don't forget to put your marks in cell B3( This formula is for cell B3, if you put your marks in any other cell please replace the B3 with that cell name)