Hi there!
To solve this problem you will need to use the cross product method :
M&Ms :
1 pound = $1.99
3.4 pounds = X
1.99 × 3.4 = X
6.766 = X
6.77 ≅ X
So she spent $6.77 on M&Ms
Skittles :
1 pound = $2.25
2.6 pounds = X
2.25 × 2.6 = X
5.85 = X
So she spent $5.85 on skittles
$6.77 + $5.85 = Total amout of money she spent on candy
$12,62 = YOUR ANSWER
There you go! I really hope this helped, if there's anything just let me know! :)