I need help with my math question

Find the missing number. a. 3 : 24 = : 72 b. : 18 = 5 : 9 c. 6: = 36 : 36

If a =6, what is the value of 2a(3b + 5c)?

Mario is constructing a frame for 10 in. by 8 in. photo. he wants the frame to be the same with all the way around in the same area of the frame and photo to be 120 square inches what is the dimension of the frame?