Question 12 of 17intermediate🔧 ApplyShort Answer4 marks
A snail is trying to climb along the wall of a deep well. During the day it climbs up 'u' cm and during the night it slowly slips down 'd' cm. This happens for 10 days and 10 nights. (a) Write an expression describing how far away the snail is from its starting position. (b) What can we say about the snail's movement if d > u?
(a)
Answer
10u - 10d cm (or 10(u - d) cm)
(b)
Answer
If d > u, the snail slips more than it climbs each cycle, so it will move backwards (net negative progress) and never escape the well.
Explanation
(a) The snail climbs 10u cm in 10 days and slips 10d cm in 10 nights. Net progress = 10u - 10d. (b) When d > u, the expression 10u - 10d becomes negative, meaning the snail ends up below where it started.