1.  If a is an odd number and b is an even number, then which of the following must be an even number ? 

Hint
Halfnhalf Clue
 

2.  If f(x, y) = 2 y  x^{2} where x and y are real numbers, then f( f(4, 7), 7) is equal to 
 Halfnhalf Clue
 

3.  If a and b are both odd numbers, then which of the following must be an odd number ? 
 Halfnhalf Clue
 

4.  Last month, Mr. Anderson spent 5% of his salary to pay his electricity bill, 12% to pay his phone bill, and 63% for general monthly expenses. If his salary is $ 3100, then his savings last month was 
 Halfnhalf Clue
 
