Math-11-LE1-2015a - MATHEMATICS 11 FIRST LONG EXAM 1st...

MATHEMATICS 11 1st SEMESTER AY 2015-2016
FIRST LONG EXAM 14 September 2015
INSTRUCTIONS. This exam is for 90 minutes. Use black or blue pen only. Show ALL necessary
solutions and BOX all final answers. The use of electronic devices is not allowed. Any form of
cheating in examinations or any act of dishonesty in relation to studies such as plagiarism shall be
subject to disciplinary action.
I. Write TRUE if the statement is always true. Otherwise, write FALSE. (1 pt. each)
1. The set { x ∈ N | 0 < x < 5 } is finite.
2. If A = { 1 , 2 , 4 } and B = { 1 , 2 , 3 , 4 , 5 } , then A - B = { 3 , 5 } .
3. If X and Y are two disjoint sets, then n ( X ∩ Y ) = 0.
4. The statement 2( x + y ) + z = z + 2( x + y ) is justified by the commutative law of addition.
5. All real numbers have a multiplicative inverse.
II. Do as indicated.
1. If X = [ - 3 , 5) and Y = { y ∈ R | y ≥