Suppose the cost stock is x and the cost of fund is y.
Total cost of Nora's portfolio:
100x+200y=3800.....i
Total cost of Erin's portfolio
300x+50y=5350...ii
solving the simultaneous equation by elimination method we proceed as follows:
multiplying eqn by 3 and subtracting ii we get:
550y=6050
thus
y=6050/550
y=11
next, multiply ii by 4 and subtracting i we get:
1100x=17600
x=16
thus the cost of Technology stock was $16 and the cost of mutual fund was $11
