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251/11 = 22 soaps(22 scraps) and 9 scraps
22 scraps leaves 2 more soaps(22+2(2 scraps))
that 2 scraps will be added with 9 scraps to get 1 more soap(22+2+1(1scrap))

So final answer is 25 soaps...

If for every 3 wrappers I get 1 soap free ( with wrapper of course )
How many soaps do I need to buy to get 20 soaps

Easy one.....
for every 3 soaps we get 1 more soap

3=4(3+1)
6=8(6+2)...