Solution a has twice as much solute as solution b is it possible for the solutions to have the same concentration

Yes. As long as the ratio of solute and solvent is same for both solution, the solution has the same concentration. for example, solution A has 2 ml of water, and 1 ml of sucrose. Solution B has 4ml of water and 2ml of sucrose. Both has a ratio of water to sucrose by 2 : 1. they have the same concentration of 50% sucrose. 

The answer is true for your question.

Adozen is 12, and your needing to calculate the weight of one medium egg, so i would do 21/12=1.75 per egg, and check your answer by doing 1.75 * 12= 21 : ) : ): ): ): ) i hoped i