8gbio logy

x+y=2x, then x:y=……….
A. 1:2 B. 2:3 C.3:4 D. 3:5 E. 4:5

1. The ratio 27:36 , expressed as a percentage, is
   A. 25% B. 45% C. 60% D. 75% E. 80%
   5.The ratio 2:x , expressed as a percentage , is 40%, then x=………..
   A. 3 B. 4 C.5 D. 6 E.8
2. If a:b=3:8 and b:c=4:5, then a:c=…………..
   A. 5:11 B. 3:8 C. 3:11 D. 3:10 E. 5:8
3. If a:b=3:5 and b:c=3:5, then a:b:c=………
   A. 2:3:5 B.3:5:7 C.6:10:15 D. 9:15:25 E.9:20:27
4. If a:b = 5:3 , then 3a+ 4b: 4a+3b is
   A. 27:36 B. 29:27 C. 27:29 D. 26:29 E. 17:19
   A. {(1,5)} B. {2√3+3} C. {3±2√3} D.{3-2√3} E. None of these
   7.x2-0.4x+k is a perfect square if k=……….
   A. 0.4 B. 0.04 C.-0.04 D.-0.4 E. 0.2
5. x2-6x+k=(x+2)2, then
   A. k=3,a=-3 B. k=9,a=3 C. k=-9,a=-3 D. k=9,a=-3 E. k=3,a=9
6. x2+8x+10+k is a perfect square if k=………..
   A. -1 B.6 C.15 D.26 E .None of these
7. Which must be added to x2-2x/3 in order to be a perfect