Question

A man has only 20 paisa coins and 25 paisa coins in his purse. If he has 50 coins in all totaling rs 11.25. How many coins of each kind does he have?

Answer 1

$\bold \color{green} { \underline { \underline \red{ \green\star \: required \: answer}}} \star$

Let the number of 20 paisa coins be x and that of 25 paisa coins be y. then,

$\bold{x + y = 50}$

total value of 20 paisa coins = 20x paisa

total value of 25 paisa coins = 25y paisa

$\bold{so \: that \: \: 20x + 25y = 1125 }\\ \bold{ \implies4x + 5y - 225 = 0}$

now by using corss-multiplication, we have

$\bold{\frac{x}{ - 225 + 150} = \frac{ - y}{ - 225 + 20} = \frac{1}{5 - 4} }$

$\bold{\implies \frac{x}{25} = \frac{y}{25} = \frac{1}{1}}$

$\bold{\implies \: x = 25 \: \: and \: y = 25}$

hence, there are 25 coins of each kind..