Question

A lady has only 20 Paise coins and 25 Paise coins in her purse. If she has 50 coins in all totalling rupees 11.50, how many coins of each kind does she have

Answer 1

see.....let the no. of 20 and 25 paise coins in her purse be x and y respectively!...
total paise she have = 11.5×100=11500
then, x+y=50 (i
and 20x + 25y =11500 (ii
multiplying first by 20 and subtracting from ii we get,
5y =150
y=30 then x = 20

Answer 2

Let the number of 20 paise coins be x and the 25 paise coins be y.

= > 20x + 25y = 1150. 

= > 4x + 5y = 230 ------ (1)

Given that she has 50 coins in total.

= > x + y = 50.   ----- (2)

On solving (1) & (2) * 4, we get

4x + 5y = 230

4x + 4y = 200

-----------------------

         y = 30



Substitute y = 30 in (2), we get

= > x + y = 50

= > x + 30 = 50

= > x = 20.



Therefore the number of 20 paise coins = 20.

Therefore the number of 25 paise coins = 30.


Hope this helps!