i think a row of 5 squares would be sufficient.
this includes a header column and a header row.
it would look like this:
tickets sold A C S T
99 66 22 187
if you don't include the headers, then a row of 4 squares would be sufficient.
the calculations would be as follows:
you are given that:
A/C = 3/2
A/S = 9/2
from this you can derive the following:
C/A = 2/3
S/A = 2/9
if you solve for C, you get C = 2A/3
if you solve for S, you get S = 2A/9
by default, A = A/1.
you are given that A + C + S = 187
by substitution, this becomes A + 2A/3 + 2A/9 = 187
multiply both sides of this equation by 9 to get 9A + 6A + 2A = 1683
combine like terms to get 17A = 1683.
solve for A to get A = 99.
you get:
A = 99
C = 2A/3 = 66
S = 2A/9 = 22
that's your solution.
from your selections, your solution will be:
The number of adults tickets sold was 99.
The number of senior tickets sold was 22.
The number of child tickets sold was 66.