Question

Start with 2 Rabbits.Each pair has 4 babies per month.How much will they have by the 12 month?

Answer 1

2 4 8 16......

the sequence represents geometric progression with first term a = 2 and common ratio r = 2

sum of geometric progression = S =  a(r^n-1)/(r-1), where n is number of terms

n =12

S = 2( 2^12 - 1)/ (2-1)

S = 8190

total rabbits by the 12 month = 8190

Answer 2

2 Rabbits multiplied by 4 equals 8 multiplied by 12 equals 96.