Probability of collision in $1^{st}$ insertion $= 0$

Probability of collision in $2^{nd}$ insertion $= \frac{1}{50}$

Probability of collision in $3^{rd}$ insertion $= \frac{49}{50} * \frac{2}{50}$

Probability of collision in $4^{th}$ insertion $ = \frac{49}{50} * \frac{48}{50} * \frac{3}{50}$

Probability of collision in $5^{th}$ insertion $= \frac{49}{50} * \frac{48}{50} * \frac{47}{50} * \frac{4}{50}$

Now, adding all these, we get $\text{Required Probability} = 0.1864$

Probability of collision in $2^{nd}$ insertion $= \frac{1}{50}$

Probability of collision in $3^{rd}$ insertion $= \frac{49}{50} * \frac{2}{50}$

Probability of collision in $4^{th}$ insertion $ = \frac{49}{50} * \frac{48}{50} * \frac{3}{50}$

Probability of collision in $5^{th}$ insertion $= \frac{49}{50} * \frac{48}{50} * \frac{47}{50} * \frac{4}{50}$

Now, adding all these, we get $\text{Required Probability} = 0.1864$