105.DS, the sum of four consecutive odd numbers is 12 less than the sum of four consecutive even numbers, ask for the least among the odd numbers?
a) the sum of four consecutive odd numbers is 48.
b) the sum of four consecutive even numbers is 60.
my answer: D.

106. one rectangle with perimeter of 18*Sqr2 is inscribed by two identical squares(there is a picture which shows: the two squares are turned 45 degree so that one vertex of a diagonal of one square touches one vertex of a diagnoal of the other inside the rectangle, and the rest of vertex of each diagonal of two squares just touches the edge of length and width of the rectangle. I hope that I made it clear), ask for the perimeter of a square?
my answer: 12.
2*(a^2) = ((1/2)*L)^2, 2*(a^2) = w^2, 2(L+w)=18*Sqr2, get a=3

107. 3x + 7y = 9, ask for ratio?
my answer: -3/7

108. pick up 2 from 12 items, the order does not matter, How many
selections are there?
My answer: C(2, 12) = 66.

109. sb A finishes the first 10 miles with speed of 40miles/hr, and the rest of 20 miles with speed of 60miles/hr, ask average speed?
my answer: 51.4

110. DS. two kinds of balls in a box, A and B, pick two balls from the box,
ask the probability that at least one A ball is picked?
a) A:B=3:1
b) the total balls in the box is less than 20.
My: e

111. which of following satisfy f(ab)=f(a)f(b)?
My: f(x)=Sqr(x)