A low-pressure weather system is approaching Plainville; rainfall results from about 70 percent of such systems in the Plainville area. Moreover, the current season, spring, is the time of year in which thundershowers, which sometimes result from low-pressure systems, are most likely to occur in Plainville. Knowing which one of the following, in addition to the information above, would be most useful for determine the probability that Plainville will have a thundershower soon?

70 % of such Low pressure system in Plainville result in rainfall.
Thunder storms from such system are very likley in spring . (C) will give us this % but for not specifically for spring. Whereas B will us spring rainfall that are thunder storms.

We know there is a 70% chance of rainfall. Ot this 70% if we know the percentage that are thunderstorms, which (B) promises to reveal we will know the probability of thunderstorm. Suppose (B) says there is a 40% of spring rainfall are thunderstorms. We can say there is a 28% chance of thunderstorms.
If (C) tells us there is a 40% chance of thunderstorm from low pressure is more exact than the Premise - Moreover, the current season, spring, is the time of year in which thundershowers, which sometimes result from low-pressure systems
IMO B

kstv wrote:A low-pressure weather system is approaching Plainville; rainfall results from about 70 percent of such systems in the Plainville area. Moreover, the current season, spring, is the time of year in which thundershowers, which sometimes result from low-pressure systems, are most likely to occur in Plainville. Knowing which one of the following, in addition to the information above, would be most useful for determine the probability that Plainville will have a thundershower soon?

70 % of such Low pressure system in Plainville result in rainfall.
Thunder storms from such system are very likley in spring . (C) will give us this % but for not specifically for spring. Whereas B will us spring rainfall that are thunder storms.

We know there is a 70% chance of rainfall. Ot this 70% if we know the percentage that are thunderstorms, which (B) promises to reveal we will know the probability of thunderstorm. Suppose (B) says there is a 40% of spring rainfall are thunderstorms. We can say there is a 28% chance of thunderstorms.
If (C) tells us there is a 40% chance of thunderstorm from low pressure is more exact than the Premise - Moreover, the current season, spring, is the time of year in which thundershowers, which sometimes result from low-pressure systems
IMO B

I think I get it~thank you so much