How many cubes are needed to pack the solid box?

a. 15
b. 20
c. 13
d. 16

D. 16

Step-by-step explanation:

If we look down the right side, we see 8 cubes.

There are 8 cubes on the left side

8+8 = 16

a. -0.3 > -0.33

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4