Question 855442
Let girl age be x.
Mother age=2x
father age =2x + 5
sum of the ages =100
x + 2x + 2x +5 = 100
5x = 100 - 5
5x = 95
x = 95/5
x =19
sarah age=19
mother age=2*19=38
father age=38+ 5=43