Answers

2016-08-02T22:14:26+08:00
X = no. of coins for .20;
y= no. of coins for .50

x + y =64 coins;  x=64-y..........1

.2 (x) + .5 (y)=18.50;
.2x +.5y =18.50........................2.

[email protected];
.2(64-y) +.5y =18.50;
12.8-.2y +.5y =18.50
12.8 +.3y = 18.50;

.3y=18.5-12.8;
.3y=5.7;
y=19.....ans  (19 pcs of 50cents)
x=64-19;
x=45.....ans ( 45 pcs of 20 cents)

checking..
.2(45) + .5 (19)= 18.50
9 + 9.5 = 18.50
    18.50=18.50

0