 
 <prompt> Bayan an kama mutane 100 a birnin, mutane 400 daga jama'a asalin sun kama. Kowace shekara bayan nan, jama'a ta kasance yarjejeniyar. Bayan shekara 4, jama'a ta kasance 60. Ayya shekaru ne mutane suka kasance a birnin a kan gaba? <response>: ```Idan mutanen suna nufin yin hankali to a gefe guda biyu, to a gefe na uku, mutanen suna nufin 60 a gefe na hudu * 2 = mutane 120 a gefe na hudu.
A gefe na biyu, mutanen suna nufin 120 a gefe na uku * 2 = mutane 240 a gefe na uku.
Kuma a gefe na daya, mutanen suna nufin 240 a gefe na uku * 2 = mutane 480 a gefe na uku.
Mutane suna nufin fitowa a gefe na daya, saboda haka idan aka saukar da su za a samu cewa mutane suna nufin 480 a gefe na uku + mutane 400 sun fito = mutane 880 a gefe na uku.
Sannan idan aka saukar da mutane saboda mutane saboda haka akwai mutane 880 – mutane 100 sun fito = mutane 780.

Wannan zai zama 780.``` 