Question 843447
Increased by 15% means multiply the number by (1 + 15/100).<P>
Call the number x.  x * (1 +.15) = 128<P>
x + .15x = 1.15x = 128<P>
x = 128/1.15 = 128/(115/100) = 128 * 100/115 = 12800/115