What is the hidden number

What is the hidden number? 5–15–25– -100

The correct answer and explanation is:

Let’s analyze the number sequence:

5 –– 15 –– 25 –– ? –– 100

We are asked to find the missing number in this pattern. First, observe the pattern in the numbers:

• The difference between 15 and 5 is:
  15 – 5 = 10
• The difference between 25 and 15 is:
  25 – 15 = 10

So far, we have a consistent pattern: the sequence increases by 10.

Following this pattern:

• Next number should be:
  25 + 10 = 35

Now let’s test whether continuing this pattern fits with the last number in the sequence (100):

• Next term:
  35 + 10 = 45
• Next:
  45 + 10 = 55
• Keep adding 10:
  65, 75, 85, 95, 105

So if we continue adding 10, we will reach 105, not 100. This tells us that the sequence does not continue with just +10 steps after a certain point.

Let’s consider this variation:

5 → 15 → 25 → ? → 100

Suppose the pattern is three terms increasing by 10, then a jump to 100.

From 25 to 100, the difference is:
100 – 25 = 75

We are missing one number between 25 and 100. This suggests a possible arithmetic jump or multiplicative transformation.

Let’s consider what number can fit logically between 25 and 100.

Try:
25 → ? → 100

Try 50:

• 25 → 50 → 100
• 50 – 25 = 25
• 100 – 50 = 50
  This is not consistent.

Try 55:

• 25 → 55 → 100
• 55 – 25 = 30
• 100 – 55 = 45
  Still inconsistent.

Try 65:

• 25 → 65 → 100
• 65 – 25 = 40
• 100 – 65 = 35
  Still no pattern.

Now try 50 again but look at a new perspective:

Original sequence:
5 → 15 → 25 → ? → 100

Check how many steps it would take to go from 5 to 100 increasing by 10:

• 5, 15, 25, 35, 45, 55, 65, 75, 85, 95, 105

But 100 isn’t part of that.

Let’s try a mixed pattern:

• First three terms: +10 each
• Then skip to 100

How do we get from 25 to 100?
Let’s try multiplying:
25 × 4 = 100

So, perhaps the hidden number is 25 × 2 = 50

Then:
5 → +10 → 15 → +10 → 25 → ×2 → 50 → ×2 → 100

That works! The pattern is:

• +10
• +10
• ×2
• ×2

✅ Final Answer: 50

Explanation:

The number pattern begins with two additions of 10:
5 + 10 = 15, 15 + 10 = 25

Then it switches to multiplication:
25 × 2 = 50, 50 × 2 = 100

Thus, the hidden number is 50, following a logical pattern of two additions followed by two multiplications.