Look at this series: 97, 97, 97, 87, 87, 87, 67, 67, 67 ... What number should come next?  Choices.
A) 47	B) 57	C) 45	D) 48	E) 55
Explanation:   In this series, each number 20 is subtracted from previous number to arrive at the next number.   Answer: Option 57
<result>B</result>
Look at this series: 97, 97, 97, 87, 87, 87, 67, 67, 67 ... What number should come next?