Answer
There are necessary 25h of sleeping to burn the kilocalories in this meal.
Work Step by Step
According to the Table 3.10 (Page 73), a 70.0 kg person, while sleeping, burns 60 kcal per hour. We can use this as a conversion factor.
As we have calculated in 3.61b, the total kilocalories in this meal is equal to 1510 kcal.
$1510 kcal \times \frac{1h}{60 kcal} = 25.16666667 h$
Rounding that value to the correct number of significant figures: $25h$
