Answers

2014-08-15T19:27:32+05:30
Let x = Least Valued Prize
Seven prizes would be 

x + 20 
x + 40 
x + 60 
x + 80 
x + 100 
x + 120 
We will add all these and put the sum equal to 700.
i.e., 7x + 420 = 700 »
As a result we get the value of x = 40, which is the least prize.
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2014-08-15T20:51:52+05:30
Answer is 40.  Because, if we purchase Rs.20/- as least value prize, there should not be '0' rupees prize.  Hence, the least value prize is Rs.40/-

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