The height of a meeting room that's measures 19 m by 12 m is 3 m. glen plans to apply 2 coats of paint to the walls of the room. a 4 l can of paint covers about 30m
what is the surface area of the walls to be painted? how many cans of paint will glen need?

So this meeting room is 3 by 19 by 12

surface area/wall area=2(height times width)+2(height times depth)+2(width times depth)

lets say 3=height
depth=19
width=12

2(3 times 12)+2(3 times 19)+2(12 times19)=2(36)+2(57)+2(228)=72+114+456=642

2 coats of paint so surface area times 2
642 times 2=1284
assuming 30m means 30 square meters we divide 1284 by 30 and get
1284/30=42 and 4/5 or 42.8
then find how many cans by dividing by 4
42.8/4=10 and 1.4/2=10.7, but you cant buy 0.7 of a can so round up and get
11 cans of paint

he needs 11 cans of paint

8,400-6,400=xx/6,400anyways the percent increase is 31.25% or 0.3125 you can round if you can