Please help with one of these

Ngrid mixes 3.6 pounds of almonds with some raisins to make a trail mix. she divides the trail mix into 12 equal portions. each portion weighs 0.7 pound. how many pounds of raisins did she use to make the trail mix? express the answer to the nearest tenth.

How do you find the area of a triangle

Hi, can anyone show me how to do this problem? 100 points for this. in advance