我想問一條Maths題,題目是:「中六級同學往大嶼山宿營。若每間房住7名學生,則有3人沒有房間;若每間房住8名學生,便有

設有x間房, y名學生, 就有
y = 7x + 3
y = 8(x-1)
所以, 7x + 3 = 8(x-1)
7x + 3 = 8x - 8
3 + 8 = 8x - 7x
x = 11
Therefore, 有11間房
y = 8(x-1) = 8(11-1) = 8*10 = 80
Therefore, 有87名學生

2006-12-29 19:12:06 補充：
Sorry! 最後果句係Therefore, 有80名學生

Let no. of students be X and
no.of rooms be Y,


7Y+3=X -----(1)

8(Y-1)=X
8Y-8=X -----(2)

(2)-(1), Y-11=0
Y=11

Sub Y=11 into (1), 7(11)+3=X
X=80


---> there are 80 students and 11 rooms