Question

1. the thickness of each book is 3.8 cm and each book stand is 5.5 cm wide. a bookshelf holds 45 books and 2 book stands. how long, in meters, is the bookshelf?
2. lu is stringing beads to make a necklace. she is using 30 of the 8 mm beads, 70 of the 4 mm beads, and 40 of the 2 mm beads. how long, in centimeters, will her finished necklace be?

Explanation:

Question 8

Step1: Calculate total thickness of books

Each book is 3.8 cm thick, and there are 45 books. So total thickness of books is \( 3.8 \times 45 \).
\( 3.8 \times 45 = 171 \) (cm)

Step2: Calculate total width of book stands

Each book stand is 5.5 cm wide, and there are 2 book stands. So total width of book stands is \( 5.5 \times 2 \).
\( 5.5 \times 2 = 11 \) (cm)

Step3: Calculate total length of bookshelf in cm

Add the total thickness of books and total width of book stands: \( 171 + 11 = 182 \) (cm)

Step4: Convert cm to meters

Since 1 meter = 100 cm, divide total length in cm by 100: \( \frac{182}{100} = 1.82 \) (meters)

Step1: Calculate total length of 8 mm beads

There are 30 beads of 8 mm each. So total length is \( 30 \times 8 = 240 \) (mm)

Step2: Calculate total length of 4 mm beads

There are 70 beads of 4 mm each. So total length is \( 70 \times 4 = 280 \) (mm)

Step3: Calculate total length of 2 mm beads

There are 40 beads of 2 mm each. So total length is \( 40 \times 2 = 80 \) (mm)

Step4: Calculate total length in mm

Add the lengths from all beads: \( 240 + 280 + 80 = 600 \) (mm)

Step5: Convert mm to cm

Since 1 cm = 10 mm, divide total length in mm by 10: \( \frac{600}{10} = 60 \) (cm)

Answer:

1.82 meters

Question 9