Answer:
1.75
Step-by-step explanation:
If a and b are two numbers, then their arithmetic mean is
[tex]\dfrac{a+b}{2}[/tex]
Given:
[tex]10a+10b=35[/tex]
Divide this equation by 10:
[tex]a+b=3.5[/tex]
Now, divide it by 2:
[tex]\dfrac{a+b}{2}=\dfrac{3.5}{2}\\ \\\dfrac{a+b}{2}=1.75[/tex]