Question

plzz solve Q 12 in the following image

Answer 1

let two rupee coin = x
50paisa coin = y
acc to question 
x = y+7 ....(i)
2x+(0.50)y = 76.50
2(y+7)+(0.50)y = 76.50  ......from(i)
2y+14+0.50y = 76.50
2.50y+14=76.50
2.50y=76.50-14
2.50y=62.50
y=$\frac{62.50}{2.50}$
y=25....put in (i)
x=y+7
x=25+7
x=32

Answer 2

Let the number of ₹2 coins be x
and number of 50 paise coins be y, then
according to the question;
x=y+7
y=x-7 --------------(i)

50 paise = ₹ (1/2)
The total values of the coins :

2x+(1/2)y = 76.50
4x+1y = 153
y = 153-4x ----------(ii)

Comparing equation (i) & (ii) , we get ;
x-7 = 153-4x
5x = 160
x = 32
_______________________
y = x-7
y = 32-7
y = 25

______________________
hence there are 32 ₹2 coins and 25 ,50 paise coins.