Answer:
the ratio of lengths of the two rods, Aluminum to Invar is 11.27
Step-by-step explanation:
coefficient of linear expansion of aluminum, 
Coefficient of linear expansion of Invar, 
Linear thermal expansion is given as;

The increase in length of Invar is given as;

The increase in length of the Aluminum;


Therefore, the ratio of lengths of the two rods, Aluminum to Invar is 11.27