Question

5.A total of 324 coins of 20 paise and 25 paise
make a Sum of Rs.71. The number of 25
paise coins is:
a) 120 b}124 c) 144 d)200​

Answer 1

$\huge{\mathfrak{\underline{\underline{Solution:-}}}}$

$\sf{Let\:the\:no.\:of\:20\:paise\:coins=x}$

$\sf{No.\:of\:25\:paise\:coins=324-x}$

$\sf{Amount\:with\:20\:paise\:coins=Rs.\:0.20x}$

$\sf{Amount\:with\:25\:paise\:coins=Rs.\:[0.25(324-x)]}$

$\sf{=Rs.\:[81-0.25x]}$

$\sf{According\:to\: Question,}$

$\sf{0.20x+[81-0.25x]=71}$

$\sf{\implies -0.05x+81=71}$

$\sf{\implies -0.05x=-10}$

$\sf{\implies x=200}$

${\boxed{\boxed{\sf{No.\:of\:20\:paise\:coins = 200}}}}$

${\boxed{\boxed{\sf{No.\:of\:25\:paise\:coins = 124}}}}$