Answer:
Step-by-step explanation:
Let x be 20-cent stamps & y be 30-cent stamps
Total stamps = 46
x + y = 46 -----------------------(I)
Total worth = $ 11.90
0.2x +0.3y = 11.90 -------------------(II)
Multiply equation (I) by (-0.2)
(I)*(-0.2) -0.2x - 0.2y = -9.2
(II) 0.2x + 0.3y = 11.90 {Now, add and x will be eliminated}
0.1y = 2.70
[tex]y=\frac{2.70}{0.1}\\[/tex]
y = 27
Plugin the value of y in equation (I)
x + 27 = 46
x = 46 - 27
x = 19
Number of 20-cent stamps = 19
Number of 30-cent stamps = 27
