19. The real number k lies between 0 and 1. The area of the quadrilateral formed by the lines y = kx, y = kx + 1, X = ky and x = ky + 1 is O 1/(1 -K) O K/(1 -K) O 1/(1 -K2) O K/(1 -K2) O K2/(1 -K2)18. Let y=(0.2x)/(x+1). If x takes all values in the range [1,) then what range of values does y take? O [0.1, 0.2) O (0, 0.1] O (0, 0.2) O [0, 0.1] O [0.1, 0.2]16. Let cot(0)=a. What is the value of cot(0)+cot(20)? O (3a2-1)/(2a) O (1+3a2)/(2a) O (a2+2a -1)/(2a) O (a+1)2/(2a) O (a2+1)/(2a) 17. If 4* -5(2*) = -6, then the value of x is O 1 or log23 O 1 or log32 O 1 or -3/2 O 1 or log42 O None of A to D is correct15. In the diagram below there are two squares. The smaller square has sides of length x. The larger square has sides of length x+y. The area of the small square is one third of the area of the large square. What is the value of x/y ? (3\"2 + 1)/2 1 [(3)112 1/9 31/2 31/2 _ 1 13. How many pairs of integers (x,y) satisfy either of the following two equations: 0 2x+2y=2("+y} o 3" 3y=3xy O o O 1 O 2 O 3 O infinite 11. A boy walks at 4 km per hour and runs at 6 km per hour. If he runs to school instead of walking, then he saves 3 minutes and 45 seconds. How far does he live from school? 0.1 25 km 0.375 km 0.75 km 6.9 km 7.5 km 20. A square has centre (2,1). One vertex is at (5,6). Points P, Q, R have coordinates P := (-3, 4), Q := (-1, -4) and R := (5, -4). Which of the following are vertices of the square? O P, Q and R O P only O P and R only O Q only O P and Q only14. Two squares of side 2x overlap to form a regular octagon. How long is each side of the octagon? 2x/ 3 X(2 _ 21/2) (21/2/2)x 2x(21/2 1) 12. We can write the number 384 as 4(2)4 where the brackets denotes a negative digit, so that 4(2)4 means 4x1002x10+4. How could we write 1988 in this way? 2(1)0(2) zoom) 2U)2Q) 2 (1) (1) (2) 20(1)(2)