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if4rnorespeed of the passenger train. Find the avelase speA certain group of students uses the internet services for a monthly charges of 48C.students join the group, each would pay R200 less. Find the number of students in the group in thebeginning |
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Answer» Let the number of students is x and per student pay Rs. y per monthsox*y = 4800 ------------(1)as 4 more students join and each pay 200 lessso(x+4)(y-200) = 4800x*y -200x +4y - 800 = 4800put the value of x*y from the (1) equation4800 - 200x + 4y - 800 = 480050x - y - 200 = 0y = 50x + 200 -------------(2)put the value of y from (2) equation in the (1) equationx(50x + 200) = 480050x² + 200x = 4800x² + 4x - 96 = 0x² + 12x - 8x - 96 =0x(x + 12) - 8(x + 12) = 0(x+12)(x-8) = 0x+12 = 0x = -12orx-8 = 0x = 8as the number of students can not be negativesoat the beginning number of students = 8and per students pay 8*y = 4800y = Rs.600 in the beginning |
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