Write one Microsoft excel formula that works for conditions below on cell C1 for any number:

a) IF A1+B1<=4, return $20
b) IF A1+B1>4 but <=9, return $35
c) IF A1+b1>9 but <=14, return $50
d) And IF A1+B1>15, return $75

To write a formula in cell C1 that satisfies the given conditions, you can use nested IF functions. Here's the formula you can use:

=IF(A1+B1<=4, $20, IF(A1+B1<=9, $35, IF(A1+B1<=14, $50, $75)))

Here's an explanation of how the formula works:

1. The outermost IF function checks if the sum of A1 and B1 is less than or equal to 4. If true, it returns $20.
2. If the condition in the outermost IF function is false, it moves to the next nested IF function.
3. The second IF function checks if the sum of A1 and B1 is greater than 4 but less than or equal to 9. If true, it returns $35.
4. If the condition in the second IF function is false, it moves to the next nested IF function.
5. The third IF function checks if the sum of A1 and B1 is greater than 9 but less than or equal to 14. If true, it returns $50.
6. If the condition in the third IF function is false, the last value $75 is returned, which means the sum of A1 and B1 is greater than 15.

Remember to replace A1 and B1 in the formula with the actual references to the cells where you have the numbers.