Which strategy would not correctly solve this story problem?

it took dennis twice as long to walk to the park as it did to walk to the store. he walked to the store in 15 minutes. he spent 5 more minutes walking to the library than to the store. how much time did dennis spend walking?

a.
work backward. start with 5 minutes and add it to 15. then add 15 more minutes to the sum to find the total time dennis walked.

b.
use logical reasoning. dennis walked for 2 periods of 15 minutes, another period of 15 minutes, and 1 more period of 15 minutes plus 5 more minutes. so dennis walked for 4 × 15 minutes plus 5 more minutes.

c.
translate into an equation. 2 × 15 + 15 + 5 + 15 = m

d.
draw a diagram. draw 2 lines and write 15 min above each line. draw another line and write 15 min above it. draw another line and write 15 + 5 above it. add up all the amounts above the lines to find the total time dennis walked.