Given that one miles walked on sand is equivalent to 3 miles on land and S stands for miles walked in sand and L the miles on land, it means mathematically that
S = 3L
That is the distance on sand is equivalent to the product of 3 and the distance covered on land.
23. 2/5 + 1/2 you find the common denominator which is 10 4/10 + 5/10 you add the fractions 9/10 he has completed 9/10 of the questions in the first 25 minutes