Joy's sister is half old as she. In two years, the sum of their ages is 43. How old is Joy's sister?
J = 2s
(J+2) + (s+2) = 2s + 2 + s + 2 = 3s + 4 = 43
Solve for s.
J = Joy's age
S = Sisters's age
Joy's sister is half old as she means:
S = J / 2
After 2 years Joy wil be J + 2 years old, Sister will be S + 2 years old
In two years, the sum of their ages is 43 means:
J + 2 + S + 2 = 43
Now:
J + S + 4 = 43
Subtract 4 to both sides
J + S = 39
Replace S with J / 2 in this equation
J + J / 2 = 39
2 J / 2 + J / 2 = 39
3 J / 2 = 39
Multiply both sides by 2
3 J = 78
J = 78 / 3
J = 26
Joy is 26 yrs old
S = J / 2 = 26 / 2 = 13
Sister is 13 yrs old
To find out how old Joy's sister is, we can set up an equation using the information given. Let's assign variables to their ages:
Let "J" represent Joy's current age.
Let "S" represent Joy's sister's current age.
Based on the given information, we know that Joy's sister is half as old as Joy, so we can write this as an equation: S = (1/2)J.
In two years, Joy will be J + 2 years old, and her sister will be S + 2 years old. The sum of their ages at that time is 43, so we can write another equation: (J + 2) + (S + 2) = 43.
Now, we have a system of two equations that we can solve simultaneously to find the values of J and S.
Let's substitute the value of S from the first equation into the second equation: (J + 2) + ((1/2)J + 2) = 43.
Now we can solve for J:
J + 2 + (1/2)J + 2 = 43
3/2 J + 4 = 43
3/2 J = 43 - 4
3/2 J = 39
J = 39 * (2/3)
J = 26
So, Joy is currently 26 years old.
To find Joy's sister's age, we can substitute the value of J back into the first equation:
S = (1/2)J
S = (1/2) * 26
S = 13
Therefore, Joy's sister is currently 13 years old.