diff --git a/src/hooks/useRandomNumbers.js b/src/hooks/useRandomNumbers.js
index e731f02..bc7300c 100644
--- a/src/hooks/useRandomNumbers.js
+++ b/src/hooks/useRandomNumbers.js
@@ -1,18 +1,15 @@
 import { useCallback, useState } from 'react'
 
 import { BOUNDS, MAX_QUANTITY, MIN_QUANTITY } from '@constants/numbers'
-import { numberGenerator } from '@utils/numberGenerator'
-import { randomNumber } from '@utils/randomNumber'
+import { getRandomNumbersFactory } from '@utils/randomNumbers'
 
-const generator = numberGenerator(...BOUNDS)
-const quantity = { min: MIN_QUANTITY, max: MAX_QUANTITY }
-const getNextNumbers = () => [...Array(randomNumber(quantity))].map(() => generator.next().value)
+const getRandomNumbers = getRandomNumbersFactory(MIN_QUANTITY, MAX_QUANTITY, BOUNDS)
 
 const useRandomNumbers = () => {
-  const [numbers, setNumbers] = useState(getNextNumbers)
+  const [numbers, setNumbers] = useState(getRandomNumbers)
 
   const nextNumbers = useCallback(() => {
-    setNumbers(getNextNumbers())
+    setNumbers(getRandomNumbers())
   }, [])
 
   return [numbers, nextNumbers]
diff --git a/src/services/storage.js b/src/services/storage.js
index aac6035..b3090ac 100644
--- a/src/services/storage.js
+++ b/src/services/storage.js
@@ -1,8 +1,32 @@
 import { firestore } from '@utils/firebase'
-import { normalizeAttempts } from '@utils/normalizeAttempts'
+import { twoDigits } from '@utils/twoDigits'
 
 const attemptsRef = firestore.collection('attempts')
 
+const parseDate = (fetchedDate) => {
+  const date = fetchedDate.toDate()
+  const year = date.getFullYear()
+  const month = twoDigits(date.getMonth() + 1)
+  const day = twoDigits(date.getDate())
+  return `${year}-${month}-${day}`
+}
+
+const normalizeAttempts = (snapshot) => {
+  const attempts = {}
+  snapshot.forEach(document => {
+    const data = document.data()
+    if (!data.end) return
+
+    const date = parseDate(data.end)
+    if (!attempts[date]) attempts[date] = [0, 0]
+
+    attempts[date][0]++
+    if (data.success === true) attempts[date][1]++
+  })
+
+  return attempts
+}
+
 export const fetchAttempts = async (uid, initDate, finishDate) => {
   const snapshot = await attemptsRef
     .where('uid', '==', uid)
diff --git a/src/utils/normalizeAttempts.js b/src/utils/normalizeAttempts.js
deleted file mode 100644
index ed48d4f..0000000
--- a/src/utils/normalizeAttempts.js
+++ /dev/null
@@ -1,25 +0,0 @@
-import { twoDigits } from '@utils/twoDigits'
-
-const parseDate = (fetchedDate) => {
-  const date = fetchedDate.toDate()
-  const year = date.getFullYear()
-  const month = twoDigits(date.getMonth() + 1)
-  const day = twoDigits(date.getDate())
-  return `${year}-${month}-${day}`
-}
-
-export const normalizeAttempts = (snapshot) => {
-  const attempts = {}
-  snapshot.forEach(document => {
-    const data = document.data()
-    if (!data.end) return
-
-    const date = parseDate(data.end)
-    if (!attempts[date]) attempts[date] = [0, 0]
-
-    attempts[date][0]++
-    if (data.success === true) attempts[date][1]++
-  })
-
-  return attempts
-}
diff --git a/src/utils/numberGenerator.js b/src/utils/numberGenerator.js
deleted file mode 100644
index 7d1e193..0000000
--- a/src/utils/numberGenerator.js
+++ /dev/null
@@ -1,7 +0,0 @@
-import { randomNumber } from '@utils/randomNumber'
-import { runOneOf } from '@utils/runOneOf'
-
-export function * numberGenerator (...bounds) {
-  const callbacks = bounds.map(([min, max]) => () => randomNumber({ min, max }))
-  while (true) yield runOneOf(...callbacks)
-}
diff --git a/src/utils/randomNumber.js b/src/utils/randomNumber.js
deleted file mode 100644
index 2d4df9e..0000000
--- a/src/utils/randomNumber.js
+++ /dev/null
@@ -1,4 +0,0 @@
-const RANDOM_NUMBER_MAX = 1_000
-
-export const randomNumber = ({ min = 0, max = RANDOM_NUMBER_MAX }) =>
-  min + Math.floor(Math.random() * (max - min + 1))
diff --git a/src/utils/randomNumbers.js b/src/utils/randomNumbers.js
new file mode 100644
index 0000000..43ac4a6
--- /dev/null
+++ b/src/utils/randomNumbers.js
@@ -0,0 +1,16 @@
+const getRandomNumber = (min, max) =>
+  min + Math.floor(Math.random() * (max - min + 1))
+
+const runOneOf = (callbacks) => {
+  const index = getRandomNumber(0, callbacks.length - 1)
+  return callbacks[index]()
+}
+
+export const getRandomNumbersFactory = (minQuantity, maxQuantity, bounds) => {
+  const callbacks = bounds.map(([min, max]) => () => getRandomNumber(min, max))
+
+  return () => {
+    const quantity = getRandomNumber(minQuantity, maxQuantity)
+    return [...Array(quantity)].map(() => runOneOf(callbacks))
+  }
+}
diff --git a/src/utils/runOneOf.js b/src/utils/runOneOf.js
deleted file mode 100644
index 61f34a2..0000000
--- a/src/utils/runOneOf.js
+++ /dev/null
@@ -1,7 +0,0 @@
-import { randomNumber } from '@utils/randomNumber'
-
-export const runOneOf = (...callbacks) => {
-  const index = randomNumber({ max: callbacks.length - 1 })
-  if (typeof callbacks[index] !== 'function') throw new Error('Invalid callback')
-  return callbacks[index]()
-}