at the start of his diet kerrin weighed 13 stone 9 pounds. three months later he weighed 12 stone 7 pounds. there are 14 pounds in a stone. calculate the reduction in kerrin's weight as a percentage of his initial weight
I did this a little differently. I converted the stones to pounds from the beginning.
13 st 9 lb. = 191 lbs. (13x14+9); 12 st 7 lbs. = 175 lbs. (12x14+7)
percent change is : amount of change /original
(191-175)/(191)= 16/191 = 0.084 or 8.4%
