Ellen is 11 years older than Maja. Last year Ellen was twice as old as Maja. How old is Maja now?

Answer 1

Maja's age now --- x
Ellen's age now ---- x+11

last year, Maja --- x-1
last year, Ellen ---- x+10

x+10 = 2(x-1)
x+10 = 2x - 2
-x = -12
x = 12

Maja is now 12 years old

check:
now:
Maja = 12
Ellen = 23

last year:
Maja --- 11
Ellen --- 22
was Ellen twice as old as Maja ? YES