Answer:
below
Step-by-step explanation:
Geometric series with first term 3 and common ratio r.
Last variety = 3 * 2^(12-1) = 6144.
Total = 3 * (2^12 - 1) / (2-1)
= 12285
10.5.
By similar triangles:
IJ / 21 = 8 /(8+8) = 1/2
IJ / 21 = 1/2
IJ = 1/2 * 21
= 10.5.
y=10