Problema Solution

The Extreme Rock Climbing Club planned a climbing expedition. The total cost was

$1400, which was to be divided equally among the members going. Prior to the trip,

15 members decided not to go. If the cost per person increased by

$21, how many people went on the expedition?

Answer provided by our tutors

Let

x = number of people that were supposed to go to the trip, x>=0
y = price per person initially with x people going

xy = 1400

y = 1400/x


(x-15)*(y+21) = 1400

plug y = 1400/x 

(x - 15)(1400/x + 21) = 1400

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click here to see the equation solved for x

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x = 40 people

x - 15 = 40 - 15 = 25 people went on the expedition.