Topic : Sequence-Geometric Sequence
1.
2.
from: category_eng

1.Mathematical Reading
Just plug in. From r*n<100, if we know r value, then we can solve it for n.
(1)r*50=500
(2)r*100+r*105=2,050

Both conditions are enough to find r.

Ans: D

2.Mathematical Writing
The rule: increased by same factor.
x=10*r
14.4=x*r

need to find the r.

14.4=10*r^2
r^2 = 144/100.
r=12/10
x=12

Discussion: 14.4 can be given as 16.9

Ans: A

1.
Plug in the number into the nth term.
2.
Follow the rule carefully. Write down traveling distance.
1. E
Understanding
Plug in the number into the nth term.
5th term is 5+2^4
6th term is 6+2^5
2. A
Understanding
Follow the rule carefully. Write down traveling distance.
8+4+4+2+2+1=