Answer: She invested $12000 in fund B.
Step-by-step explanation:
Let x represent the amount which she invested in fund A.
Let y represent the amount which she invested in fund B.
The amount she invested in Fund A was twice as much as the amount she invested in fund B. This means that
x = 2y
Fund A returned a 7% profit. It means that the profit returned from fund A is
7/100 × x = 0.07x
Fund B returned a 5% profit. It means that the profit returned from fund B is
5/100 × y = 0.05y
if total profit from the two funds together was $2280, it means that
0.07x + 0.05y = 2280- - - - - - - - - - -1
Substituting x = 2y into equation 1, it becomes
0.07 × 2y + 0.05y = 2280
0.14y + 0.05y = 2280
0.19y = 2280
y = 2280/0.19
y = 12000
x = 2y = 2 × 12000
x = 24000