Question

jamal places 1 - centimeter cubes in pairs. then he uses the pairs of cubes to make rows of different lengths.
a. what is the surface area of a row made of 30 pairs of cubes? show your work.
b. check your answer to problem 3a. show your work.

Explanation:

Step1: Analyze the dimensions of the row - made shape

When 1 - centimeter cubes are paired and arranged in a row, for 30 pairs of cubes, the length of the row \(l = 2\times30=60\) cm (since each pair has a length of 2 cm), the width \(w = 1\) cm and the height \(h = 1\) cm.

Step2: Recall the surface - area formula for a rectangular prism

The surface - area formula of a rectangular prism is \(SA=2(lw + lh+wh)\).

Step3: Substitute the values into the formula

Substitute \(l = 60\) cm, \(w = 1\) cm and \(h = 1\) cm into the formula:
\[

$$\begin{align*} SA&=2(60\times1+60\times1 + 1\times1)\\ &=2(60 + 60+1)\\ &=2\times121\\ &=242 \end{align*}$$

\]

Answer:

242 square centimeters