Prism a is similar to prism b. the volume of prism a is 2720 cm³.
what is the volume of prism b?
21,760 cm³
1360 cm³
680 cm³
340 cm³

If prism a is similar to prism b and the volume of prism a is 2720 cm^3. all answers are possible depending on the scale factor of the similar prisms. we can try each of the choices, one by one. 

if the scale factor is 1/8, the answer is 21,760 cm3
                                    2, the answer is 1360 cm3
                                    4, the answer is 680 cm3
                                    8, the answer is 340 cm3