Question

A man has only 20 paisa coin and 25 paisa coins in his purse. if he has 50 coins in all totaling rs. 11.25,how many 20 paisa coins he have?

Answer 1

Let the number of 20 paisa coins be 'x' && number of 25 paisa coins be 'y'

Given , x + y = 50....(i)
20*x + 25*y = 1125 paisa.....(ii)
(i)*20== 20x + 20y = 1000...(iii)

(ii) - (iii)== 5y = 125
y = 25
x=25

Hence number of 20 paisa coins = 25
Hope this helps

Answer 2

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

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..