To compare the speeds of the dog and the hare, let's assume that the dog takes 4 leaps in time 't' and the hare takes 5 leaps in the same time 't'.
According to the given information, 3 leaps of the dog are equal to 4 leaps of the hare. So, we can write the ratio of their speeds as:
Speed of the dog : Speed of the hare = (number of leaps taken by the dog in time 't') : (number of leaps taken by the hare in time 't')
Let's calculate the number of leaps taken by the dog and the hare in time 't':
Number of leaps taken by the dog in time 't' = 4 leaps
Number of leaps taken by the hare in time 't' = 5 leaps
Now, let's substitute these values in the ratio:
Speed of the dog : Speed of the hare = 4 : 5
This means that the speed of the dog is 4/5 times the speed of the hare.
To compare the speeds, we can simplify the ratio:
Speed of the dog : Speed of the hare = 4/5 : 1
Multiplying both sides of the ratio by 5, we get:
Speed of the dog : Speed of the hare = 4 : 5
Therefore, the correct answer is option A) 16:15. The ratio of their speeds is 16:15.