Question

Fernando gave Maria the following puzzle: I am thinking of a number. I divide it by 3. Then I divide the result by 5. The final result is 8. What is my number?

Answer 1

The student's question is about reversing the operations of division to find an original number based on a final result of 8. By working backwards and multiplying 8 by 5 and then by 3, we find that the original number is 120.

Step-by-step explanation:

The student is asking about a mathematical process involving division and finding an original number based on a given result. To work backwards from the final result, we apply the opposite operations in reverse order. Since the final number after dividing by 3 and then by 5 is 8, we first multiply 8 by 5 and then multiply the result by 3 to get the original number Fernando was thinking of.

Multiplication and division are inverse operations. Hence, if dividing by a number gets us to a certain result, multiplying by the same number will get us back to the original number. Let's use this knowledge to solve the puzzle:

1. 
   
3. 
   

Therefore, the original number Fernando is thinking of is 120.

Answer 2

To find the number we do the inverse of division, and that's multiplication. We multiply 8 x 5 x 3 to get 120, that's our number. So Fernando is thinking of the number 120, and we can prove that it's correct by dividing 120 / 3 then the result divide it by 5 and we get 8.