What is the 43rd term of an arithmetic sequence with a rate of increase of -6 and a11 = 12? -174-176-180-186-240

Hello : 
an = a1 +(n-1)d       d = -6 and  a11 = 12 
terme general : an = ap +(n-p)d
n= 43 and p = 11     a41 =a11+(43-11)(-6)
  a41 = 12 -192 = 180

The answer would be 27 because assuming that each package has 1 bar of soap and 1 tube of toothpaste, after 27 packages they would run out of toothpaste