I got the last one..maybe!(a bit confused due to the negative sign in the first term..) but the last one seems to me the most sensible answer.
Number of surface = 5
Surface 1: 8 x 5 = 40 . [The left side]
Surface 2: 15 x 5 = 75 . [The bottom side]
Surface 3: 17 x 5 = 85 . [The slanted side]
[Surface 4 and 5 are triangles and they have the same surface area]
Surface 4 : 1/2 x 15 x 8 = 60
Surface 5 : 60
Total : 40 + 75 + 85 + 60 + 60 = 320 square units
Answer:
Adults =1500 and student= 2500
Step-by-step explanation:
Step one:
GIven data
let Adults be x and student be y in numbers
so
5x+3y=15000------------1
x+y=4000---------------------2
from 1
x=4000-y, put this in 2, we have
5(4000-y)+3y=15000
20000-5y+3y=15000
-2y=15000-20000
-2y= -5000
2y=5000
divide both sides by 2
y= 2500
put y= 2500 in 2
x+2500= 4000
x= 4000-2500
x=1500
This is associative property (3, 4,) 7 4×3=12+7=19
