Question

A salmon has to swim 25 miles upstream. It seems 7 miles each day and drifts 5 miles at night. How many days does it take for the salmon to first reach the 25 mile mark?)

Answer 1

makes good 2 miles per day
after 12 day/night cycles is at the 24 mile mark
so he will just make it at dusk on the 25 th day

Answer 2

After 9 cycles he has made 18 miles
On day 10 he swims the last 7 miles.

Answer 3

Use Steve's answer

Answer 4

First, you would have to subtract 5 from 7. My answer is 2. Next, multiply 2 to 12. I get 24. Since 1 more day is remaining, add 1 to 24. The answer to the question is 25.