In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Q: Problem: r is the set of positive even integers less than 20 , and s is the set of the squares of the integers in r . how many elements does the intersection of r and s contain ? 
Options: ['a ) none', 'b ) two', 'c ) three', 'd ) five', 'e ) seven']

A: c
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Q: Problem: if a man earns rs 20 on first day and spends rs 15 on second day , and earns rs 20 on third day and spends rs 15 on fourth day and goes on on which day he will be having rs 60 . 
Options: a ) 40 rs , b ) 45 rs , c ) 50 rs , d ) 55 rs , e ) 60 rs

A: e
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Q: Problem: a trader sells 85 meters of cloth for rs . 8500 at the profit of rs . 15 per metre of cloth . what is the cost price of one metre of cloth ? 
Options: a ) rs . 80 , b ) rs . 85 , c ) rs . 90 , d ) rs . 95 , e ) none of these

A:
b
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