19
16
17
18
Given:
- Day one: 100 particles
- Day n (where n ≥ 2): One out of every n particles produces another particle.
We want to find the value of m when the total number of particles reaches 1000 on day m.
Step 1: Day Two
On day two (n = 2), half of the 100 particles produce another particle.
So, the total becomes 100 + 50 = 150 particles.
Step 2: Day Three
On day three (n = 3), one-third of the 150 particles produce another particle.
So, the total becomes 150 + 50 = 200 particles.
Step 3: Day Four
On day four (n = 4), one-fourth of the 200 particles produce another particle.
So, the total becomes 200 + 50 = 250 particles.
We can observe a pattern here: in each step, 50 particles are added.
Step 4: Day m
On day m, the total becomes 1000 particles.
From day 1 to day m, 50 particles are added in each step after day 1.
So, the number of steps from day 1 to day m is:
\(m - 1 = \frac{1000 - 100}{50}\)
\(m - 1 = \frac{900}{50} = 18\)
\(m = 18 + 1 = 19\)
Therefore, the value of m is \(19\).
Which letter replaces the question mark? A, D, G, J, M, ?
When $10^{100}$ is divided by 7, the remainder is ?