[[[急]]]數學一問!!!!

If Marcus spent 1/3 of his money,and give 2/5 of his money to Michelle,and he has $1200 left, how many money does he have original?

Let Marcus original have $y

y*(1-1/3-2/5)=1200
y*(1-5/15-6/15)=1200
y*(1-11/15)=1200
y*4/11=1200
y=3300
Therefore, Marcus original have $3300

2006-12-08 13:03:18 補充：
If the money that Marcus give to Michelle is the remaining money's 2/5The calculation will beLet Marcus original have $y y*(1-1/3)*(1-2/5)=1200y*2/3*3/5=1200y=3000Therefore, Marcus original have $3000let's see which answer is suitable for the question

2006-12-08 13:04:25 補充：
Let Marcus original have $y y*(1-1/3-2/5)=1200y*(1-5/15-6/15)=1200y*(1-11/15)=1200y*4/15=1200y=4500Therefore, Marcus original have $4500

2006-12-08 13:05:12 補充：
The above supp. is the correction of the cal. in contentSORRY about the mistake

Let a = Orihinal money

a- a/3 - 2a/5 = $1,200

(15a - 5a - 6a) / 15= $1,200

4a / 15 = $1,200

4a = $1,200 x 15

a = $4,500

Let the original money be y
y-(1/3y+2/5y)=1200
15(y-1/3y-2/5y) = 1200(15)
15y-5y-6y=18000
4y=18000
y=4500

so, the the original money of Marcus is $4500.

1200 = 3/5 *since 2/5 gave to michelle
(1200/3)*5=2000
2000/3=6000

the orginal budget is 6000.