The density of a material in CGS system of units is 4 g/cm³ . . .

Question : The density of a material in CGS system of units is 4 g/cm³. In a system of units in which unit of length is 10 cm and unit of mass is 100 g, the value of density of material will be

a) 400
b) 0.04
c) 0.4
d) 40

Doubt by Sanya

Solution : 

Dimensional Formula of Density 
[M1L-3T0]
a=1, b=-3, c=0

n1=4
M1=1g
L1=1cm

n2=?
M1=100g
L1=10cm

n2=n1[M1/M2]a[L1/L2]b[T1/T2]c
n2=4[1/100]1[1/10]-3[T1/T2]0
n2=4[1/100][10]3×1
n2=4[1000/100]
n2=4×10
n2=40

Hence, d) 40 will be the correct option.