It is not bigger. 25.879 is bigger by .100
Well, the answer would bee 1/10 for a simple reason: the 3 in 7.315 is in the tenth's spot while the 3 in 893.5 is in the ones. a one spot different that can be proven with logic.
The correct answer is 42.
5 • 8 = 40
40 + 2 = 42