Figure 4 shows two potato chips - Edexcel - GCSE Biology Combined Science - Question 2 - 2018 - Paper 1

To calculate the total surface area of potato chip B, we will use the formula:

$$ext{Total surface area} = 2XY + 2XZ + 2YZ$$

Given:

• Length of X = 5.0 cm
• Length of Y = 2.0 cm
• Length of Z = 2.0 cm

Substituting the values into the formula:

1. Calculate each part:

   • First term: $2XY = 2(5.0)(2.0) = 20.0$
   • Second term: $2XZ = 2(5.0)(2.0) = 20.0$
   • Third term: $2YZ = 2(2.0)(2.0) = 8.0$

2. Sum the three parts: $ext{Total surface area} = 20.0 + 20.0 + 8.0 = 48.0 cm^2$

Thus, the total surface area of potato chip B is 48.0 cm².