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My question is , I went to the market with 100 dollars . It was not a dollar note . It was coins , They were 50 cents , 5 dollars and 10 dollars . I bought many things . When I reached home all my 100 dollars were spent and 100 things were also there . Now tell me how much things I bought from 50 cents , 5 dollars and 10 dollars ????

Tell me the correct answer .

Hint :
100 cents = 1 dollar .

2006-12-18 00:20:15 · 10 answers · asked by Unique, 100% 1 in Science & Mathematics Mathematics

The first correct answer will recieve 10 points . Try .

2006-12-18 00:21:59 · update #1

10 answers

I'm assuming you want 100 items costing either 50cents $5 or $10 and coming to a total of $100

Each item must cost an average of $1

So for each $10, you must have 18 items costing $0.50 to maintain the average i.e. 19 items coming to a total of $19
For each $5, you must have 8 items cosing $0.50 to maintain the average i.e. 9 items coming to a total of $9

Now you need numbers that add up to 100, using only 19 and 9

9*9 + 19 = 81 + 19 = 100
So you have 1(10 + (18*0.5)) + 9(5 + (8*0.5))
1(10) + 18(0.5) + 9(5) + 72(0.5)

1 item for $10
9 items for $5
90 items for 50 cents

2006-12-18 00:37:44 · answer #1 · answered by Tom :: Athier than Thou 6 · 2 1

Well , This question is just assuming question .
First lets take 50 cents . (Let us take 50 cents as 50 c)

If we take 50 things in 50c then it's 25$ , but we need a maximum of 35+ . If we assume .

Now let's take , 90 things then it is 45$ .

Let's take 5$
What we need is 10 things and 55$ . The rule is it has to be 5$ and 10$ . So , we can't take 10 things and finish because the dollars add up to 75$ only . Then we take the next number 9 .

9*5=45$

90+9=99

45$+45$=90$ .

Now let's take 10$ ,

We need 1 thing and 10$ . So , we finish the problem by adding one thing to 99 , which costs 10$ .

we add:

99+1=100

and

90$+10$=100$ .

Thus , the one and only solution is 50 cents = 90 things , 5 dollars = 9 things and 10 dollars = 1 thing .

Thank you for giving an opportunity to prove my skills in maths and to use my brain for some time .

Thank you once again .

-----------------------------------*---------------------------*-------------------

2006-12-18 08:56:18 · answer #2 · answered by Anonymous · 0 0

These are called Diophantine equations in the first degree( solvable only in integers). Since u bought 100 things and assuming of course that u are a sweet girl who never cheats, we can assume that the total number of coins u had was 100 and their monetary value was hundred too. Let us say that the number of 50 cent coins u had was l, 5 dollars m and 10 dollars n.
then we get the equations,
0.5l+5m+10n=100
and
l+m+n=100
l=100-n-m.
Go back and substitute n in the first equation and after simplification,
You get
9m+19n=100
m=9 and n=1 is one of the solutions.
By a popular result in Diophantine analysis, the other solutions are given by
m=9+19t and n=1-9t
where t is an integer. It is easy to see that for any value of t other than 0, either m or n will be negative.
So,
m=9, n=1,l=100-9-1=90.
so u initially had 90 50 cent cions, 9 5dollar coins and 1 10dollar coin. By the logic i had used before, u must have also purchased 90 items from 50cent coins, 9 items from 5dollar coins and 1 from 10$ coin.

2006-12-19 06:05:42 · answer #3 · answered by Anonymous · 0 0

Let us denote the number of 50¢ things you bought as a, the number of $5 things as b, and the number of $10 things you bought as c. Then:

a∈N, b∈N, c∈N
a+b+c=100
a/2 + 5b + 10c = 100

Solving the system of equations:

a+b+c -2(a/2 + 5b + 10c) = 100 - 200
-9b - 19c = -100
9b + 19c = 100
9b = 100-19c
b=(100-19c)/9

Now b∈N, so 100-19c must be an exact multiple of 9. Thus:

100-19c ≡ 0 mod 9
100≡19c mod 9
c≡ 1 mod 9

Since clearly c=10 would not work, we have c=1. Thus:

b=(100-19)/9 = 81/9=9

And finally:
a=100-9-1=90

Thus a=90, b=9, c=1

2006-12-18 08:32:11 · answer #4 · answered by Pascal 7 · 1 0

90 items for 50 cents,9 items for 5$ and 1 item for 10$

2006-12-18 09:33:05 · answer #5 · answered by siddharth_ram 2 · 0 0

Things purchase 1 for 10 Doller, things purchase 9 for 5 Dollers each and 90 things purchase of 50 cents each

2006-12-18 08:30:56 · answer #6 · answered by Anonymous · 0 1

Things rate($) $
1 X 10 = 10
9 X 5 = 45
90 X 0.5 = 45
---------------------------------------------
100 things for 100 dollar
=========================

i think you got correct solution.

2006-12-18 09:27:46 · answer #7 · answered by sundar k 2 · 0 0

That's right.. no single answer..

x - number of things you bought for 10c
y - for 5$
z - for 10$..

x+y+z= 100 things
x*0.1 + y*5 + z*10 = 100$

.. no single answer... you need to predefine one of the variables... the it will be solvable..

2006-12-18 08:41:11 · answer #8 · answered by Munja 1 · 0 1

I dont understand!!

2006-12-18 09:00:40 · answer #9 · answered by Anonymous · 0 2

no single solusion(?)

2006-12-18 08:24:03 · answer #10 · answered by JAMES 4 · 0 2

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