Answer: About 45.
Step-by-step explanation: There's always a pattern in these kinds of questions, you can see for 9th to 13th August, the number has always been between 20 to 40. And since on 13th August the graph is on a rise again, it would be around 45. 90 is just not realistic considering there's only an increase of around 5-10 tickets every day.
Let x be the unknown number
x×55%=121
x=121÷55%
x=220
So 121 is 55% of 220
1 solution
x = -1/2
-------------------------------------
The correct answer is choice d because you would divide x by 2 to get 70. then you do the same with y so 35/2 = 17.5