Question 1
Answer is 54.

Workings
1 + 3 = 4
The formular used to arrive at this is
a + b= ab + a
Now, lets verify.
1 + 3 = 1 *3 + 1= 4
2 + 4 = 2 *4 + 2 =10
3 + 5 = 3 *5 + 3= 18
Now i have verified my formular.

Then
6 + 8 = 6 * 8 + 6 = 54

The answer is 54

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I dont get the second question.