18. How much heavier is an average woman's brain than an average woman's heart in pounds (lb)?

To solve the problem, we need to find the average weights of a woman's brain and heart, and then calculate the difference between the two weights. 1. **Average weight of a woman's brain**: The average weight of an adult human brain is approximately 3 pounds (lb). This can vary slightly, but for our purposes, we will use this average. 2. **Average weight of a woman's heart**: The average weight of an adult human heart is about 0.5 pounds (lb). Now, we can calculate how much heavier the average woman's brain is than her heart: \[ \text{Difference} = \text{Weight of Brain} - \text{Weight of Heart} \] Substituting the values: \[ \text{Difference} = 3 \, \text{lb} - 0.5 \, \text{lb} \] Now, let's perform the calculation: \[ \text{Difference} = 2.5 \, \text{lb} \] Thus, the average woman's brain is 2.5 pounds heavier than her heart.