Explanation :
1 turtle in each tank = 1 turtle too many
2 turtles in each tank = 1 tank too many
Using one of the better known heuristic to solve this question
Before that, we know that:
2 turtles in each tank = 1 tank too many
2 turtles in each tank = 2 turtles short
First, find the difference in the number of turtles in the two scenarios:
First scenario = 1 turtle too many
Second scenario = 2 turtles short
Difference in turtles = 1 - (- 2)
Difference in turtles = 3
Second, find the difference in the distribution of turtles:
First scenario = 1 turtle each tank
Second scenario = 2 turtles each tank
Difference in turtle = 2 - 1
Difference in turtles = 1
Find the number of tanks:
Number of tanks = 3 ÷ 1
Number of tanks = 3
Find the number of turtles:
Using the first scenario, there was one turtle too many
Number of tanks = 3
Number of turtles = 3 + 1
Number of turtles = 4
There are 4 turtles and 3 tanks.