Inactive Tutor answered 01/07/14
Me Y.
asked 01/07/14amount originated
if a man spends one fifth of what is in his wallet and then one fifth of what remained, and has spent $72.00, what was the amount originally in his wallet?
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4 Answers By Expert Tutors
Tutor
New to Wyzant
Sorry Robert & Vivian for calling y'all out, but I think y'all have erred.
The man originally had $200 in his wallet.
He spent 1/5 of what was in his wallet, which is $40. Then $160 remains. Then if he spends 1/5 of what remains, that's $32. Thus he's spent a total of $40+$32 = $72.
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1) One way of solving this is to first say that "x" represents the total originally in the man's wallet.
2) If he spends 1/5 of what's in his wallet, he's spent (1/5)x, and that means that there's still (4/5)x in his wallet.
3) Then if he also spends 1/5 of what remains, he spends an additional (1/5)*(4/5)x.
4) The total he's spent thus far, then, is given by (1/5)x + (1/5)*(4/5)x. The problem tells us that equals $72, so we can solve:
(1/5)x + (1/5)*(4/5)x = 72
(1/5)x + (4/25)x = 72
(5/25)x + (4/25)x = 72
(9/25)x = 72
x = 72 * (25/9) = 8 * 25 = 200.
So he originally had $200 in the wallet.
Hello Me -- another angle: the 2nd outlay must be 4/5ths of the 1st outlay "x" ...
1.8x = $72 ... 72 over 1.8 ... scale up by 2/3rds ... 120 over 3 ... x= $40 ...
since the 1st outlay of $40 is 1/5th of original wallet ==> $200 to start ... Regards :)
Inactive Tutor answered 01/07/14
Tutor
New to Wyzant
Hi Me;
Sorry, Me. After Murtaza's correction, I decided it was time to go to sleep.
x=original amount
He spent (1/5)th of x. Then, (4/5)ths remained and he spent (1/5)th of that.
[(1/5)(x)]+[(1/5)(4/5)x]=$72.00
[(1/5)x]+[(4/25)x]=$72.00
[(5/25)x]+[(4/25)x]=$72.00
(9/25)x=$72.00
Let's multiply both sides by (25/9)...
(9/25)(25/9)x=$72.00(25/9)
x=$200.00
Inactive Tutor answered 01/07/14
Tutor
New to Wyzant
Let x be the original amount.
Balance by spending,
x - (4/5)^2 x = 72, focusing on the remaining part each time.
Solve for x,
x = $200
Answer: The original amount was $200.
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Hi Murtaza;
You are correct. I misread the problem. This problem can be done as above.
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Inactive Tutor
01/07/14