A group of friends planned a trip and chartered a bus for $247.50. When they got four more friends to join the trip, the cost for the bus was $6 less per person. In all how many people made the trip? please show work, thanks
2007-03-31 07:19:57 · 3 answers · asked by jimyj 1 in Science & Mathematics ➔ Mathematics
247.5/ x = cost per person originally
247.5/(x+4) = cost per per person after 4 more joined
247.5/x - 247.5/(x+4)= 6
So 247.5(x+4) -247.5x = 6x(x+4)
247.5x + 990 -247.5 x = 6x^2 +24x
6x^2 +24x -990 = 0
x^2+4x-165 = 0
(x +15)(x-11) = 0
x-11= 0
x = 11
x+ 4 = 15 = # of people making trip
2007-03-31 07:42:37 · answer #1 · answered by ironduke8159 7 · 1⤊ 0⤋
247.50 / ( n+4) = 247.50 / n -6
247.50 n = 247.50(n+4) - 6n(n+4)
6n^2 +24n = 4*247.50
6(n+2)^2 = 4*247.50 +24 = 1014 = 6 * 13^2
so n = 13-2 = 11
so in all there were 15 making the trip
2007-03-31 07:26:26 · answer #2 · answered by hustolemyname 6 · 0⤊ 0⤋
Let x = number of people on the trip.
247.50/x + 6 = 247.50/(x-4)
2007-03-31 07:28:56 · answer #3 · answered by Anonymous · 0⤊ 0⤋