Let Rosemary's age = X
and Hannah's age = Y
According to question,
X + Y = 102 … (i)
X - Y = 52 … (ii)
Adding the equation (i) + (ii)
We get,
2X = 154
X = 77
now putting the value of X in Equation (ii)
We get,
77 - Y = 52
Y = 77-52
Y = 25
Hence, Rosemary's age =77 and Hannah's age = 25