Maricko reads 12 pages per day. So, if we cumulate the pages read with each day, the cumulative tally would look like this:
[tex] 1 \text{ day} \implies 12 \text{ pages} = 1\cdot 12\text{ pages} [/tex]
[tex] 2 \text{ days} \implies 12+12 \text{ pages} = 2\cdot 12\text{ pages} [/tex]
[tex] 3 \text{ days} \implies 12+12+12 \text{ pages} = 3\cdot 12\text{ pages} [/tex]
So, in general, after [tex] d [/tex] days, Maricko will have read [tex] d \cdot 12 [/tex] pages.
Since in your case [tex] d=10 [/tex], Maricko read
[tex] 10\cdot 12 = 120 [/tex] pages while on vacation.
