two sisters together have 20 books. if the younger sister lost 3 books and the older sister doubled the number she has, they would have a total of 30 books. How many books does each have?
2 answers
The older has 26 and the younger 4
Now:
older sister --- x
younger sister --- 20-x
new scenario:
older sister --- 2x
younger --- 20-x - 3 = 17-x
2x + 17-x = 30
x = 13
so now the older has 13, the younger has 7
older sister --- x
younger sister --- 20-x
new scenario:
older sister --- 2x
younger --- 20-x - 3 = 17-x
2x + 17-x = 30
x = 13
so now the older has 13, the younger has 7