Use the goalseek function for the same.

"Frances C" wrote in message
...
I will like to know if is posible to create a formula that can calcalculate
the following two problems

a1=200 * b1=2% - c1=o = result in D1 should be 4
a1=200 * b1=0% - c1=50 = result in D1 should be 150

Note the result can not be a negative number

Thanks

Frances