Question

The masses of the three wires of copper are on the ratio of 1:3:5 and their length are in the ratio of 5:3:1. the ratio of their electrical resistance is

Answer 1

mass  ratio  of 3 wires
1 : 3   : 5 

lengths  are in ratio
5 : 3: 1

V = A * L

V = pi*r^2 * L

density = d

m = V*d

m = A*L * d 

A = m/(L *d)

R = p*L/A

p is constant for all copper  so now we just have to find the  ratio of L to area
since  d = density of copper  it is constant too ..  so  the only variables are 

A varies  m/L



R varies  L/A

R varies by  L/ (m/L)

R varies by L*L/m

R varies by L^2/m

first wire 

R1 = 5^2/1 = 25

R2 = 3^2/3 = 3

R3 = 1^2/5 = 1/5

the resistance vary by 

25 : 3: 1/5

or 

125 : 15 : 1

Answer 2

Hello dost

Refer to attachment :)