The total subscriber count of a media platform drops by 15% during the first year, grows by 30% in the second year, and drops again by 10% in the third year. If the initial number of subscribers was 40,000, what will be the subscriber count at the end of 3 years?

The correct answer is 39,780.

Step 1: Identify the given initial value and yearly changes.
Initial subscriber count = 40,000
Year 1: Drops by 15%
Year 2: Grows by 30%
Year 3: Drops by 10%

Step 2: Calculate the subscriber count at the end of Year 1.
A drop of 15% means the subscriber count becomes 85% (or 0.85) of its initial value.

$\text{Count after Year 1}=\mathrm{40,000}\times \left(1-0.15\right)=\mathrm{40,000}\times 0.85=\mathrm{34,000}$

Step 3: Calculate the subscriber count at the end of Year 2.
A growth of 30% means the subscriber count becomes 130% (or 1.30) of the Year 1 count.

$\text{Count after Year 2}=\mathrm{34,000}\times \left(1+0.30\right)=\mathrm{34,000}\times 1.30=\mathrm{44,200}$

Step 4: Calculate the subscriber count at the end of Year 3.
A drop of 10% means the subscriber count becomes 90% (or 0.90) of the Year 2 count.

$\text{Count after Year 3}=\mathrm{44,200}\times \left(1-0.10\right)=\mathrm{44,200}\times 0.90=\mathrm{39,780}$

Thus, the total subscriber count at the end of 3 years is 39,780.