Atank is 25 m long, 12 m wide and 6 m deep. the cost of plastering its walls and bottom at 75 paise per sq. m, is:

U can solve it by long wall short wall method

1) inner plastering

long wall (25m)
L = 25
H = 6m
no. of plastering = 2 ( in a tank, 2 walls of same length( rectangle tank))
plastering = 25*6*4
= 600 square meter

similarly , short wall (12m)
L = 12m
B= 6m
plastering = 12*6*2
=144 square meter

2) outer plastering
here we include, thickness of wall
long wall (25m)
L=25m
H=6m
wall thickness = 0.9m
no. of plastering = 2 ( because, 2 identical walls)
plastering = 25×(2×.9)
=22.5 square meter

similarly, short wall
plastering = 12×(2×.9)
= 10.8 squaremeter

3) bottom portion
L = 25m
B= 12m
plastering = 25×12
= 300 square meter

cost for plastering
total no. of plastering ( 600+144+22.5+10.8+300)
coast of plastering = 75 paise per Sq. m

= 1080×75 paise
= 8100 paise
= Rs. 810

i hope it's helpful

Let x and y be the respective new co ordinates so,

according to the question ,
the coordinate system is up by 5 units so,
means that the values at 0 will be to 5 , 1 to 6..
so the is
y=y+5
so y=y-5

now the coordinate system is also in x direction by 3 units to left so,
x=x-3
x=x+3
so, the coordinates to represent any line, point, graph on the    system was
(x,y)
after the respective the new coordinates that should be used are
(x+3,y-5)

(note that even if x is performed first then the y even then it will yield the same result)