Question

the dimensions of a cuboid are in the ratio 5:3:2 . given that it's volume as 810 sq. cm, find it's total surface area....
pls explain each step.....​

Answer 1

let the length, breadth and height be 5k, 3k and 2k.

Volume=810

or, l×b×h=810

or,5k×3k×2k=810

or,30k=810

or,k=27

or,k=3

So,

l=5k=5×3=15cm

b=3k=3×3=9cm

h=2k=2×3=6cm

Now,

TSA of cuboid=2(lb+bh+lh)

=2(15×9+9×6+15×6)

=2(135+54+90)

=2×279=558cm

Hope it helps you

Answer 2

Answer:

15 ,9,6

Step-by-step explanation:

let the common factor between the ratio be x.

therefore sides are:-

5x,3x and 2x

Since volume is given as 810 sq.cm

therefore

volume of the cuboid =product of its sides

810=5x*3x*2x

30x³=810

x³=27

x=3

therefore sides

5x= 5*3=15

3x=3*3=9

2x=2*3=6