Question 271049
T = 3L "Trisha is 3 times  as old as Lilly."
L = 2E "Lilly is twice as old as Emma."
So T = 3(2E) = 6E.
T+L+E = 27 "...the sum of the three girls' ages is 27."
Perform the substitutions:
6E+2E+E = 27 Simplify.
9E = 27 Divide by 9.
E = 3