Daniel gave 4/5 of his stickers to Javier. Javier’s collection of stickers increased to 64. If Javier had 28 stickers in the beginning, how many stickers did Daniel have in the beginning?

so 4/5 of Daniel's stickers = 64

1/5 of Daniel's stickers = 16
5/5 of Daniel's stickers = 80

Let's assume Daniel had x stickers in the beginning.

Daniel gave 4/5 of his stickers to Javier, which means he gave away (4/5)x stickers.

After receiving stickers from Daniel, Javier's collection increased to 64, so we can write the equation:

28 + (4/5)x = 64

To solve for x, we can start by subtracting 28 from both sides of the equation:

(4/5)x = 64 - 28

Simplifying the equation further:

(4/5)x = 36

To isolate x, we multiply both sides by the reciprocal of 4/5, which is 5/4:

[(4/5)x] * (5/4) = 36 * (5/4)

Simplifying the equation:

Canceling out the common factors on both sides:

x = 45

Therefore, Daniel had 45 stickers in the beginning.

To solve this problem, we can use a proportion. Let's assume that Daniel had x stickers in the beginning.

According to the information given, Javier started with 28 stickers and after receiving 4/5 of Daniel's stickers, his collection increased to 64 stickers.

We can set up a proportion:

(x - 4/5x) / 28 = (64 - 28) / 28

Simplifying the equation, we get:

(1/5x) / 28 = 36 / 28

Now, cross-multiply:

(1/5x) * 28 = 36

Multiply both sides by 5:

28x = 180

Divide both sides by 28:

x = 180 / 28

Simplifying, we get:

x ≈ 6.43

Therefore, Daniel had approximately 6.43 stickers in the beginning. Since we cannot have a fraction of a sticker, we can say that Daniel had 6 stickers in the beginning.