Question

If 9999=4, 8888=8, 1816=6, 1212=0 then how much is 1919=?

Answer 1

9999 has 4 enclosed areas and only one type of digit =4×1=4
8888 has 8 enclosed area and only one tile of digit =8×1=8
1816 has 2 enclosed area and 3 type of digits
2×3=6

so 1919 has two enclosed area and two type of digits =2×2=4

Answer 2

Hey mate,
This is more of riddle than math problem.

◆ Answer-
1919 => 2

◆ Explanation-
Let's look at the given numbers carefully.
9999 has 4 holes(°) in it so 9999 => 4
8888 has 8 holes in it so 8888 => 8
1212 has no holes in it so 1212 => 0

Now let's see 1919, it has 2 holes in total so,
1919 => 2


Hope this helps...