1. a jar contains 100 marbles total. some are black. if you pull 4 marbles out and 1 is black
how many out of the 100 marbles would you guess are black?

The number of black marbles in a jar containing 100 marbles  is ;  25 black marbles

Given that:

Jar contains 100 marbles

out of every 4 marbles pulled, 1 marble  = black

∴ probability of picking a black marble = 1/4

Determining the number of black marbles contained in 100 marbles

= 1/4 * Total number of marbles

= 1/4 * 100 marbles =  25 black  marbles

Hence we can conclude that the number of black marbles in a jar  containing 100 marbles = 25 black marbles

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cuz some people don't have enough food. that's why we need more ppl to donate food to the hungry.

increases the risk of extinction 

explanation:

the answer is that if the species suffers from the disease, there is nothing stronger than the others, so it is possible to remove wholeness. an example of this is hunger in irish potatoes, which has a deadly disease bearish part of all potato harvest masses. pretty much ruins the land of crops.