F+G:

Then, add the elements that occupy the same position:

Solve

So, we find the element at address h31:

In this case, position h31 is - 8.0
The answer is
date
1 2 3 4 5 31
r1 r2 r3 r4 r5 . . . r31
1gm 2gms 3<span>gms 4gms 5gms . . . 31gms
r1+r2+ .... +r31= 31(31+1) /2=496gms (31 rings)
he only made 5 rings
31 rings----------> 496 gms
5 rings ------------> ? = 5 x496 / 31=80 gms
</span><span> the weights of those 5 rings was 80 gms</span>