The ratio of Harry's stamps to Ronnie's stamps was 6 to 1. Harry gave half of his stamps to Ronnie. He added his remaining stamps and found that he now had 11 fewer stamps than Ronnie. How many stamps did Harry have at first?
Ronnie had R stamps at first
Harry had 6R
After Harry gave 1/2 of his stamps to Ronnie
(1/2) * 6R + 11 = R + (1/2) (6R)
3R + 11 = R + 3R
3R + 11 = 4R
11 = 4R - 3R
11 = R
Harry had 6*11 = 66 stamps at first