Answer:
hey mate
surface area of cuboid is 2(lh+bh+hl)
doing for first cuboid
h = 20
l = 6
b = 5
surface area for this cuboid on calculating u get 500 sq.cm
now
second cuboid
h = 12
l = 6
b = 4
calculaye it by formula and u get 288 sq.cm
so total surface area is 500 + 288 = 788 but in this one side is getting counted 2 times which is rectangle with length 6 and 12 so it's area is 12×6 = 72
final ans = 788-72 = 716 cm2
as per me that's ans
brinliest pls