To solve for the number of horses (h) that the trainer can train using 42 mints, with 5 mints needed per training session, we start with the equation:
\( 5h = 42 \)
Now we can solve for \( h \):
- Divide both sides by 5: \[ h = \frac{42}{5} = 8.4 \]
Since \( h \) represents the number of horses, which must be a whole number, 8.4 is not a viable option because you cannot train a fraction of a horse.
Therefore, the correct response is:
5h = 42, so h = 8.4 horses, which is not viable.