The problem consists of four sub-problems involving division of fractions. We need to calculate "how many times" one quantity is compared to another, which translates to a division problem.

1. Problem Description

The problem consists of four sub-problems involving division of fractions. We need to calculate "how many times" one quantity is compared to another, which translates to a division problem.

2. Solution Steps

Problem 2:

The question asks: $\frac{9}{10}$ is how many times $\frac{6}{5}$?

This means we need to calculate $\frac{9}{10} \div \frac{6}{5}$.

To divide fractions, we multiply by the reciprocal of the divisor.

$\frac{9}{10} \div \frac{6}{5} = \frac{9}{10} \times \frac{5}{6}$.

Now we simplify:

$\frac{9}{10} \times \frac{5}{6} = \frac{3 \times 3}{2 \times 5} \times \frac{5}{2 \times 3} = \frac{3 \times 3 \times 5}{2 \times 5 \times 2 \times 3} = \frac{3}{2 \times 2} = \frac{3}{4}$.

Problem 3:

The question asks: $\frac{15}{16}$ is how many times $\frac{9}{8}$?

This means we need to calculate $\frac{15}{16} \div \frac{9}{8}$.

To divide fractions, we multiply by the reciprocal of the divisor.

$\frac{15}{16} \div \frac{9}{8} = \frac{15}{16} \times \frac{8}{9}$.

Now we simplify:

$\frac{15}{16} \times \frac{8}{9} = \frac{5 \times 3}{2 \times 8} \times \frac{8}{3 \times 3} = \frac{5 \times 3 \times 8}{2 \times 8 \times 3 \times 3} = \frac{5}{2 \times 3} = \frac{5}{6}$.

Problem 4:

The question asks: $1\frac{3}{8}$ is how many times $\frac{5}{12}$?

First, we convert the mixed number to an improper fraction: $1\frac{3}{8} = \frac{1 \times 8 + 3}{8} = \frac{11}{8}$.

Now we need to calculate $\frac{11}{8} \div \frac{5}{12}$.

To divide fractions, we multiply by the reciprocal of the divisor.

$\frac{11}{8} \div \frac{5}{12} = \frac{11}{8} \times \frac{12}{5}$.

Now we simplify:

$\frac{11}{8} \times \frac{12}{5} = \frac{11}{2 \times 4} \times \frac{3 \times 4}{5} = \frac{11 \times 3 \times 4}{2 \times 4 \times 5} = \frac{11 \times 3}{2 \times 5} = \frac{33}{10}$.

This can be written as $3\frac{3}{10}$.

3. Final Answer

Problem 2: $\frac{3}{4}$

Problem 3: $\frac{5}{6}$

Problem 4: $\frac{33}{10}$ or $3\frac{3}{10}$