Posted by Lena on Sunday, June 7, 2009 at 1:57pm.
I don't think I am understanding this question.
Question:
A zoo started with 16 cranes and panned to hatch 20 chicks. A few birds were kept for breeding and the rest realeased into the wild. At the end of last year, a total of 136 cranes had spent some time in the zoo. If the pattern continues, how many cranes will there be by the end of this year? the next year?
My thinking:
I don't know how many cranes they kept so I called that 'x'
I know they hatch 20 cranes a year so the number of years it took to get to 136 cranes would be 136/20 = 6.8 years
So by the end of the year would be 7 years so 20 x 7 = 140 cranes
So by the end of next year would be 140 + 20 = 160

Math  Lena, Sunday, June 7, 2009 at 2:13pm
planned to hatch 20 chicks a year* CORRECTION

Math  Yasmeen, Sunday, December 4, 2016 at 2:48pm
The equation would actually be 16+(n1)(20) because they initially started off with 16 cranes so 16=a and they increase every year by 20 cranes so d=20 so plug the values into a+(n1)d. There would be 156 cranes at the end of this year and 176 by the next year.