Respuesta :

Answer:

42

Step-by-step explanation:

Answer:

42

Step-by-step explanation:

Let Joanne age be x

let betty age by y

. ° . x + y = 60

if joanne is 18

y = 18

x + 18 = 60

x = 60 - 18

x = 42

. ° . betty = 42