Let's break down and analyze the mathematical problems from your image:

1. Problem 18:

This involves basic operations with scientific notation. The two subproblems are:

• (a) $1.6 \times 10^5 \div 4 \times 10^2$
• (b) $8.8 \times 10^8 \times 3.3 \times 10^{-4}$

Both require the use of rules for multiplying and dividing numbers in scientific notation.

2. Problem 19:

Again, this asks to simplify expressions involving powers of 10:

• (a) $4 \times 10^7 \div 8 \times 10^3$
• (b) $2.1 \times 10^{-8} \times 6 \times 10^9$

These also require multiplying or dividing the numbers and combining powers of 10.

3. Problem 22:

Here, the task involves writing two movie box office values in both decimal and scientific notation formats.

The movies and box office values provided are:

• "Wonder 2" with $250.7 million
• "Secret Life of Pets" with $368.4 million

For this, the decimal values will need to be converted into scientific notation (e.g., $2.507 \times 10^8$).

4. Problem 23:

This involves geometry, specifically a right triangle:

• Given: The dimensions of a giant rectangular prism are given. The height and the prism's base diagonal need to be calculated using the Pythagorean Theorem.

Would you like me to solve each of these step-by-step?