Question
A MAN SAVED #8 THE FIRST DAY #16 THE SECOND DAY #32 THIRD DAY AND SO ON.HOW MANY DAYS WOULD IT TAKES HIM TO SAVE A TOTAL SUM OF #2040
Answers
mathhelper
8, 16, 32 , ...
looks like GP with a = 8, r = 2
sum(n) = a(r^n - 1)/(r-1)
2040 = 8(2^n - 1)/(2-1)
255 = 2^n - 1
2^n = 256
I know 2^7 = 256
so n = 7
I will take 7 days
looks like GP with a = 8, r = 2
sum(n) = a(r^n - 1)/(r-1)
2040 = 8(2^n - 1)/(2-1)
255 = 2^n - 1
2^n = 256
I know 2^7 = 256
so n = 7
I will take 7 days
oobleck
2^8 = 256