SOLUTION: how many bricks,each of dimensions 20cm*12cm*9cm,will be required to build a wall 12m long 72cm thick 4m hight.

Algebra.Com
Question 709234: how many bricks,each of dimensions 20cm*12cm*9cm,will be required to build a wall 12m long 72cm thick 4m hight.
Found 2 solutions by MathLover1, jsmallt9:
Answer by MathLover1(20850)   (Show Source): You can put this solution on YOUR website!

bricks,each of dimensions , required to build a wall long, thick height:
first find a volume of a wall:
.......


now find a volume of a brick dimensions


now divide a volume of a wall by a volume of a brick



....... bricks required to build a wall

Answer by jsmallt9(3758)   (Show Source): You can put this solution on YOUR website!
The solution from the other tutor is correct. But it is only correct because the each side of the wall can be divided evenly by a corresponding side of a brick. So a full, proper solution will first determine this divisibility.

The 20cm side of the brick will divide evenly into the 4m side of the wall: 4m = 400cm and 400/20 = 20

The 12cm side of the brick will divide evenly into the 12m side of the wall: 12m = 1200cm and 1200/12 = 100

The 9cm side of the brick will divide evenly into the 72cm side of the wall: 72/9 = 8

This makes the number of bricks needed: 20*100*8 = 16000 (which matches the answer from the other tutor).

P.S. When checking for the divisibility, try all possible combinations. In this problem, the 20cm side of the brick divides into both the 12m and 4m sides of the wall. The 12cm side of the brick divides into both the 72cm and 12m sides of the wall. But the 9cm side of the brick only divides evenly into the 72cm side of the wall. This leaves the 12m for the 12cm and then the 20cm into the 4m.

P.P.S. If you cannot find this divisibility then it will not be possible to build the wall unless you break off parts of the bricks. This is a more difficult problem to solve and the solution from the other tutor, to divide the volumes, will not work correctly.

RELATED QUESTIONS

how many bricks each measuring 25cm*11.25cm*6cm will be needed to build a wall 8m long,6m (answered by mananth)
how many bricks of length 20cm will be needed to keep along the foot of a wall of 80... (answered by josmiceli)
how many bricks each 8 in . by 2 3/4 in. by 2 in. will be required to build a wall 22 ft. (answered by josmiceli)
Suppose 826 bricks are used in constructing a wall 14 feet long. How many bricks will be... (answered by Fombitz)
if 20 men can build a wall in 5 days how many men will be required to build the same wall (answered by Theo)
if 20 men can build a wall in 5 days how many men will be required to build the same... (answered by greenestamps,ikleyn)
In how many ways can bricks be laid to fill a wall of length 6 feet using bricks which... (answered by stanbon)
who+many+briks+each+of+size+23cm+11.5+cm+8+cm+will+be+required+to+build+a+wall+of+size+11. (answered by KMST)
A certain number of masons can build a wall in 14 days. If the number of masons is... (answered by ewatrrr)