Ne(g) effuses at a rate that is times that of kr(g) under the same conditions.

                  Ne effuses at a rate that is 2.05 times that of Kr under the same conditions

                  According to Graham's Law of Effusion, "the rate of effusion of a gas is inversely proportional to the square root of its density or molar mass".

Mathematically,

                                      Rₐ / Rₓ  =      ----- (1)

Where;

           Rₐ  =  Rate of effusion of Ne

           Rₓ  =  Rate of effusion of Kr

           Mₐ  =  Molar Mass of Ne  =  20.18 g.mol⁻¹

           Mₓ  =  Molar Mass of Kr  =  84.80 g.mol⁻¹

Putting values in equation 1,

                                      Rₐ / Rₓ  =  

                                      Rₐ / Rₓ  =  

                                      Rₐ / Rₓ  =  2.05

         Hence, Ne effuses 2.05 times faster than Kr.

the answer is d. 74.02