Question

there are 7 shelves of books. 5 shelves are 1.2 m long. 2 shelves are 1.5 m long. what is the total length of the 7 shelves?
a rock star can sign 36 photographs in a minute. how many can he sign in 30 seconds?
shana has read 5 pages of a 20-page comic book. if it has taken her 9 minutes, how long is it likely to take her to read the whole comic book?

Explanation:

Step1: Calculate length of 5 shelves

$5 \times 1.2 = 6$ m

Step2: Calculate length of 2 shelves

$2 \times 1.5 = 3$ m

Step3: Sum total shelf length

$6 + 3 = 9$ m

Step4: Convert time to match rate

30 seconds = $\frac{1}{2}$ minute

Step5: Calculate signed photos

$36 \times \frac{1}{2} = 18$

Step6: Find time per page

$\frac{9}{5} = 1.8$ minutes per page

Step7: Calculate total time for 20 pages

$20 \times 1.8 = 36$ minutes

Answer:

1. 9 meters
2. 18 photographs
3. 36 minutes