Answer:X+(X+10)+(2X)
Explanation:
Lets say X is the amount of children tickets sold.
So she sold some kid tickets and we get an X
So X
and then she sold ten more than X tickets to adults
So now we have
X+(X+10)
And then she sold twice as many senior tickets than kids tickets
so now we have
X+(X+10)+(2X)
hope that helped at all!