Question

7. The dimensions of a cuboid are a, b, c units, its volume is V cubic units and its whole surface area is
S sq. units. Then, is 1/v is
(a) s/2 (a+b+c)
b) 2/s(1/a+1/b+1/c)
(c) 2s (a + b + c)
(d) 2s/(a+b+c)

Answer 1

Answer:

Option b

Step-by-step explanation:

V=abc

S=2(ab+bc+ac)

1/V=1/abc=(1/a+1/b+1/c)/abc(1/a+1/b+1/c)

              =(1/a+1/b+1/c)/(ab+bc+ac)

              =(1/a+1/b+1/c)/s/2

              =2/s(1/a+1/b+1/c)