Final answer:
By setting up two equations to represent Liana and Siara's ages in terms of Marie's age and equating them since they are twins, we solve for Marie's age to find that Marie is 5 years old.
Step-by-step explanation:
To solve for Marie's age based on the information given, we can set up two equations. If Liana is '11 more than 3 times Marie's age,' we can write this as L = 3M + 11, where L represents Liana's age and M represents Marie's age. Similarly, if Siara is '4 less than 6 times Marie's age,' this translates to S = 6M - 4. Since Siara and Liana are twins and thus have the same age, we can set the right sides of these two equations equal to each other to solve for M:
Equating Ages of the Twins:
3M + 11 = 6M - 4
Solving for M:
Solving for M, we rearrange the equation:
- Add 4 to both sides: 3M + 15 = 6M
- Subtract 3M from both sides: 15 = 3M
- Divide both sides by 3: M = 5
Marie is 5 years old. This is the solution to the problem using basic algebra.