A person wants to buy 3 paise and 5 paise stamps costing exactly one rupee. If he buys which of the following number of stamps he won't able to buy 3 paise stamps.
Choose the correct choice from the following answers:
A) 5 B) 10 C) 15 D) 18 E) 20
let 'x' be no. of 3p stamps &amp; 'y' be no. of 5p stamps   therefr 3x+5y=100   he wont be able to buy 3p stamps iff he buys maximum quant of 5p stamps   i.e. y should be max and x min   thus lets take x=0   3(0)+5(y)=100   5y=100   y=20   thus , if he buys 20 5p stamps, he wont be able to buy 3p stamps... SIMPL20!!!   ANSW20R:20
<result>E</result>
A person wants to buy 3 paise and 5 paise stamps costing exactly one rupee. If he buys which of the following number of stamps he won't able to buy 3 paise stamps.