The ratio of guppies to angelfish in a shop was 2:3. The number of angelfish was 2/3 the number of gold fish. The shopkeeper decided to replace 1/4 of the guppies with some angelfish. The number of angelfish in the end. How many guppies were in the shop in the beginning?

I don't understand the sentence The number of angelfish in the end.

I believe your previous post said that there were then 30 more guppies than in the beginning.

That means that there were 120 to begin with, since adding 1/4 of 120 means adding 30.

However, that leaves us nothing to do with the goldfish or angelfish. I suspect you have still garbled the question. How about doing some careful proofreading? Also, no need to make a new posting again. Just add to this one.
Both versions of the problem just wander off into nonsense.

Let's denote the number of guppies in the shop as "g" and the number of angelfish as "a".

According to the given information, the ratio of guppies to angelfish in the shop was 2:3. This can be written as:

g/a = 2/3

We also know that the number of angelfish was 2/3 the number of goldfish. Let's denote the number of goldfish as "f". This relationship can be expressed as:

a = 2/3 * f

The shopkeeper decided to replace 1/4 of the guppies with some angelfish. This means that 1/4 of the total number of guppies will be subtracted from "g" and added to "a". This can be written as:

g - 1/4 * g = 3/4 * g
a + 1/4 * g

Since the ratio of guppies to angelfish remained the same, we can set up an equation using the given ratios:

3/4 * g / (a + 1/4 * g) = 2/3

To solve for g, we can substitute a with 2/3 * f and simplify the equation:

3/4 * g / (2/3 * f + 1/4 * g) = 2/3

Multiplying both sides by (3 * 4) gives:

3 * 3 * g = 2 * 4 * (2 * f + g)

Simplifying further:

9g = 16(2f + g)
9g = 32f + 16g
9g - 16g = 32f
-7g = 32f

From here, we can see that g must be a multiple of 32 since 32 divides evenly into -7g. The given information does not provide a specific value for f, so we cannot determine an exact number for g. However, we do know that if g is a multiple of 32, then the number of guppies in the shop in the beginning will be g.

To find the number of guppies in the shop in the beginning, we can follow these steps:

Step 1: Let's assume the original number of guppies as '2x'.
Step 2: According to the given ratio, the number of angelfish would be '3x' (since the ratio is 2:3).
Step 3: The number of angelfish would be two-thirds the number of goldfish. Let's call the number of goldfish 'y'. So, the number of angelfish would be (2/3) * y.
Step 4: The shopkeeper decided to replace 1/4 of the guppies with some angelfish. So, 1/4 of the original number of guppies would be (1/4) * 2x.
Step 5: After the replacement, the new number of guppies would be the original number minus the replaced guppies: 2x - (1/4) * 2x = 2x - (1/2) * x = (3/2) * x.
Step 6: According to the updated ratio, the new number of angelfish would still be '3x'.
Step 7: We need to find the final number of angelfish. Since (3/2) * x of the original guppies were unchanged, the number of angelfish would be (3x - (3/2) * x) = (3/2) * x.

Therefore, the number of angelfish in the end would be (3/2) * x.

Please note that without knowing the value of 'x', we cannot determine the exact number of guppies and angelfish. However, the calculations above show how to find the number of guppies in the shop in the beginning.