Y'' + y = e^-x help me

Pick the description of a geometric object that best matches the real world object box for a deck of card

Aclass consists of 55% boys and 45% girls. it is observed that 25% of the class are boys and scored an a on the test, and 35% of the class are girls and scored an a on the test. if a student is chosen at random and is found to be a girl, the probability that the student scored an ais

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