Aptitude - Ratio and Proportion - Discussion

To solve this problem, we first need to find the total value of each type of coin and then use the given information to determine the number of 5 p coins.

Let's denote:
-( x) as the number of 25 p coins,
-( 2x) as the number of 10 p coins (since it's twice the number of 25 p coins),
-( 3x) as the number of 5 p coins (since it's thrice the number of 25 p coins).

The total value of the coins can be expressed as:
[ 25x + 10(2x) + 5(3x) = 3000] (converted Rs. 30 into paise).

Solve for (x):

[ 25x + 20x + 15x = 3000]
[ 60x = 3000]
[ x = frac{3000}{60}]
[x = 50]
Now, we know that there are 50 coins of 25 paise each.
So, the number of 5 paise coins is ( 3x = 3 * 50 = 150).
Therefore, there are 150 - 5 paise coins in the bag.

The right answer is 150.

We can not equate quantity to value e.g 1:2:3 or 1x+2x+3x(Q) = 3000(V).

We should equate value to value e.g 25p 10p 5p or 25x 20x 15x(V) = 3000(V).

that makes 60x=3000 and x=50.

Proof:

With the answer 150 5p coins we get,

1:2:3 = 50 100 150 , 25p 10p 5p respectively makes a value of 3000p and it is logical with the given ratio 1:2:3/50:100:150 [50 coins of 25p] [100 coins of 10p] and [150 coins of 5p].

Whereas, with the answer 300 5p coins we get,

1:2:3 = 20 100 300 , 25p 10p 5p respectively, also makes a value of 3000p but it is illogical with the ratio. It can't be 1:2:3/20:100:300.

Hope you got it :).

Why can't we do like this :

25p : 10p : 5p in ratio of 1:2:3 to form total sum of 30 rupee.

So we can say that 1/6 th of 30 rupees form by 25p coins (i.e 5 rupee),
2/6th of 30 rupee form by 10p coins (i.e 10 rupee),
3/6 th of 30 rupee form by 5p coins (i.e 15 rupee).

To get 1 rupee we need 4 25p coins-for 5 * 4 = 20 coins of 25p for 5 rupee.

To get 1 rupee we need 10 10p coins-for 10 * 10 = 100 coins of 10p for 10 rupee.

To get 1 rupee we need 20 5p coins-for 15 * 20 = 300 coins of 5p for 15 rupee.

Any suggestions.

@Avi.

Please read the question again it says no of coins are in ratio 1:2:3 and not that value of 25 paise coin in total 30 rs is 1. So first find total no of coin. Then multiply it with respective denomination. You are saying as 3/6*3000=1500p so 1500/5= 300 coins. Fault is that without knowing the no of coin you straight away calculated the value of each coin although ratio is about the no of coin. Hope I have explained.

The biggest confusion here is because of value of coins and number of coins. Now the ratio 1:2:3 given is the number of coins where as 25p 10p and 5p are the value of coins.

Thus,

Value: 25p 10p 5p.

Number of coins: 1*x 2*x 3*x.

Total value: 25x 20x 15x.

Given, 25x+20x+15x=30*100 (rs. 30 converted into paisa).

60x = 3000.

x = 50.

Therefore, number of coins is 3*x.

3*50 = 150.

I think correct answer is: 300.

Let : Coin is x,

Than 25p's coin = x.
10p's coin= 2x.
5p's coin= 3x.

x+2x+3x = 30.
6x = 30.
x = 30/6 => x=5.

So. 25p's value = 5.
10p's value = 5*2 = 10.
5p's value = 5*3 = 15.

Now we get coin's no.

25p's coin 5/.25 = 20 no.
10p's coin 10/.10 = 100 no.
5p's coin15/.05 = 300 no.

Now correct answer is 300.

Can anyone solve this?

3 persons decided to have dinner together. The first person had 3 cakes, the second person had 5 cakes while the third person had nothing but being true friends they wanted to share equally among themselves but the third person wanted to compensate them with 8 gold coins that he had. Find how many coins each of them should get?

@Cutie.

Let A, B, C Shares be x, y, z respectively.
Then 8x = 12y = 6z.

From above,
x = (3/4)z.
y = (1/2)z.

Total (x+y+z) = 432.
(0.75+0.5+1)z = 432.
2.25z = 432.
z = (432/2.25).
z = 192.

From that,
x= [(3/4)*192].
= 144.
y = [(1/2)*192].
= 96.
z=192.

x+y+z = 144+96+192 = 432.

@depanshu shortcut is correct and it is the shortest method

Totally we have Rs.30 = 3000p.

25p,10p, 5p are in ratio of 1:2:3 (given).

We can also write it as
No. of coins of 25p = x
No. of coins of 10p = 2x
No. of coins of 5p = 3x

Then,
25(x)+10(2x)+5(3x)= 3000
We will find x = 50.

No. of coins of 5p = 3*50 = 150.

I think in the ques it should be 15rs then the answer is correct !

For 30Rs one shud note that 5p coins should be maximum than any other coins (25p & 10ps) since the ratio of coins is 1:2:3.

If 150 coins had to be the answer. Then 25p & 10p shud be lesser than this... which will not in anycase amount to 30rs.