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Name: Vish Who is asking: Student Level of the question: Secondary Question: Passengers boarded a plane in Phoenix. In Dallas 1/2 of the passengers got off and 4/5 of the original number got on. In Memphis 3/4 of the passengers got off and twice the number of remaining passengers got on. In Chicago 2/3 of the passengers got off the plane leaving 39 passengers. How many passengers originally boarded the plane in Phoenix? |
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Hi Vish, I would do this problem by working backwards, that is starting with the 39 passengers who are still on the plane in Chicago. When the plane arrived in Chicago 2/3 of the passengers got off so the 39 passengers remaining are 1/3 of the passengers who were on the plane when it arrived in Chicago. Thus 3 39 = 117 passengers were on the plane when it arrived in Chicago. When the plane left Memphis it had 117 passengers. In Memphis 3/4 of the passengers got off and twice the number of remaining passengers got on. Thus, after 3/4 of the arriving passengers got off there were 117/3 = 39 passengers still on the plane. These 39 people are 1/4 of the passengers who were on the plane when it arrived in Memphis and thus 39 4 = 156 passengers were on the plane when it arrived in Memphis. Now it's your turn. How many passengers were on the plane when it arrived in Dallas? When you answer that make sure you go through the process forward, from Phoenix to Dallas to Memphis to Chicago to make sure you end with 39 people still on the plane in Chicago. Penny |