Answer:
about 12 people
Step-by-step explanation:
cir.=2πr=62.8 , so r=31.4/π , vol of tower= base area × hight = πr² × 11.5 ≈ 3609.17 cm³ , number of people= vol/300 ≈ 12
Jon has y stickers and uses 20
jon=y-20
the sisters share y-20 between 2 of them
therefore each sister receives
(y-20) divided by 2 -- (y-20)/2
Answer:

Step-by-step explanation:
Rewrite the system of equations as:

Subtract the second equation from the first to isolate
:

Plug in
into any of the equations above and solve for
:

Verify that the solution pair
works 
Therefore, the solution to this system of equations is:

<span> 63 in four different ways
1) 63 ones
2) 6 tens and 3 ones
3) 3 tens and 33 ones
4) 4 tens and 23 ones</span>