document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=364075>Question 364075</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a boy have 5 coins each of different denominations. How many different sums of money he can form ? Its answer is 31 plz help </SPAN>\n" );
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document.write( "In making a sum of money, he has 2 choices for each coin: include it, or not.  With 5 coins, the number of combinations of choices he can make -- and therefore the number of different sums of money he can make -- is 2*2*2*2*2 = 2^5 = 32.<br><BR>\n" );
document.write( "One of those possibilities is 0 (if he chooses not to include every coin in his selection).  Since you say the answer to the question is 31, apparently a sum of 0 is not allowed.<br><BR>\n" );
document.write( "Since all the other sums are allowed, the number of (nonzero) sums he can make is 32-1 = 31. </SPAN>\n" );
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