Step-by-step explanation:
the volume of a regular block is
length × width × height
and we know 1 m = 100 cm.
and 1 m³ = 100×100×100 = 1,000,000 cm³
in our case
length = 15 m
width = 20 cm = 0.2 m
height = 3 m
a)
the volume of the wall without the door and the windows is simply the volume of the full wall minus the volume of the door, minus the volume of the windows.
the full-wall volume is
15×3×0.2 = 9 m³
the volume of the door (opening) is (the same width as the wall itself)
1×2×0.2 = 0.4 m³
the volume of the two windows openings (again with the save width as the regular wall) is
2 × 3×1×0.2 = 1.2 m³
so, the volume of the wall without the door and without the windows is
9 - 0.4 - 1.2 = 7.4 m³
b)
the volume of a single brick is
16 cm × 8 cm × 4 cm = 512 cm³ = 0.000512 m³
how many brick do we need ? as many as times one brick fits into the wall :
7.4 / 0.000512 = 14,453.125 bricks
since we usually cannot get parts of bricks, we have to round this up to the next full brick :
14,454 bricks.
c)
1000 bricks cost Rs.15,000.
that is a cost ratio (rate) of 15000/1000.
that means 1 brick is then 1/1000 of that : Rs.15
we need 14,454 bricks.
that would mean they cost
14454×15 = Rs.216,810
but I think the original price rate means we can only buy the bricks in packages of 1000.
so, we need to round the number of bricks to the next full 1000 : 15,000
and then the price is
15000 × 15 = Rs.225,000
so, please make sure to use the number that fits to the scenario your teacher intended: is it supposed to be based on the precise number of bricks, or on packages of 1000 bricks ? in the first case the price is Rs.216,810, in the second case the price is Rs.225,000.
