Question 450503

For each coin there is two ways, either include the coin or exclude it.

so, each coin can be selected in 2 ways, and total 5 coins

total no. of ways = 2*2*2*2*2 = 32 

but there will one single case in which no coin selected, so discard it.

total no. of ways when at least one coin= 32-1 = 31 


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