UMary usemdala ngokuphindwe kabili kuno-Elizabeth. UJohn mdala ngeminyaka emibili kuno-Elizabeth. Ubudala bukaJohane nobuka-Elizabeth uma buhlanganisiwe bulingana nesishiyagalombili. Uneminyaka emingaki uMary? Chaza ukucabanga kwakho.
Ake sithi u-Elizabeth uneminyaka engu-x. Siyazi ukuthi uJohane mdala kuno-Elizabeth ngeminyaka emibili, futhi uma behlangene iminyaka yabo ingu-8. Ngakho x + x + 2 = 8, okusho ukuthi u-Elizabeth ungu-3. UMary uneminyaka emibili kuno-Elizabeth, okwenza uMary abe neminyaka eyisithupha.