question:Look at this series: 80, 10, 70, 15, 60, ... What number should come next?
Options:
(A) 20
(B) 23
(C) 25
(D) 30
(E) 35
answer:(A)
Stream of consciousness:This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next. In the second, 5 is added to each number to arrive at the next.

question:At what rate percent on simple interest will a sum of money double itself in 30 years?
Options:
(A) 3 1/3%
(B) 3 1/8%
(C) 3 7/3%
(D) 3 1/7%
(E) 3 1/1%
answer:(A)
Stream of consciousness:P = (P*30*R)/100
R = 3 1/3%

question:The ratio of men to women in the Snyder community choir is 4 to 5. The ratio of men to women in the Leigh community choir is 5 to 6. If the two choirs merged, the ratio of men to women in the combined choir would be 22 to 27. If Snyder has 4 more men and 6 more women than Leigh, how many women are in the Snyder choir?
Options:
(A) 20
(B) 24
(C) 30
(D) 32
(E) 34
answer:
(C)
Stream of consciousness:Use simultaneous equations / By combination
4x = 5y + 4
5x = 6y + 6
Multiply (1) by 6
Multiply (2) by -5
Get rid of y, and x = 6
Then 5x = 30