Explanation:

To find the smallest perfect square divisible by both 10 and 15, follow these steps:

- Identify the least common multiple (LCM):

- Factors of 10: 2 x 5

- Factors of 15: 3 x 5

- LCM involves taking the highest powers: 2 x 3 x 5 = 30.

- Find the smallest perfect square divisible by 30:

- Perfect square needs all prime factor exponents to be even.

- Minimum requirement: \(30 = 2^1 \times 3^1 \times 5^1\).

- Make exponents even: \(2^2 \times 3^2 \times 5^2 = 900\).

Option 1: 900 is a perfect square and divisible by 30.

- Option 2, 3, 4: Not perfect squares or not smallest.