This is a surface area problem but we have to split it into 2 sections.
1. The rectangle bottom part - just remember it doesn't have a top
2. The triangle prism part - remember it doesn't have a bottom
1. SA=2(lw+lh+wh) l=10, w=6, h=5
Plug those in and solve you get 280. But you have to take off the area of the top so area of a rectangle is l*w = 60 280-60=220
2. SA=2[tex]( \frac{1}{2} bh)[/tex]+[tex] A_{1} + A_{2} +A _{3} [/tex] of each rectangar side (though in our case we are leaving one off).
b=6 h=4 A of each is 60. When you plug them all in, leaving one off, you get 124.
220+124=344 so the answer is B
I hope that helps.
