First, find the area of the shelf if it were a full circle.
the formula for the area of a circle is a=pi(r squared)
a=pi (10.5 squared)
a=pi x 110.25
a=3.14 x 110.25
a=346.185
now, you have to divide that area by 4 to get the area of the 1/4 circle
346.185/4=86.55
Answer:
88
Step-by-step explanation:
Find the prime factorization of both 8 and 11.
8 → 4 × 2 → 2 × 2 × 2
11 → 11
Then, multiply each factor the greater number of times it occurs. Since no factors are duplicated between 8 and 11 (as in, 2 is not a factor of 11, nor is 11 a factor of 8), LCM will equal 2 × 2 × 2 × 11.
2 × 2 × 2 × 11 = 88, so the LCM is 88.
It's a little hard to explain without visuals. A video could be useful, though I can't put links here.
They are essentially asking us to solve:

Solving this equation for x tells us that it will take around 80.1 years for the materials in the vault to reduce to 357 pounds.
Answer:
I think it would be 5 and 5 of each solution