geo kan

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

1. 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
2. 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
3. If 2x +3y:2x+y=3:2, then x:y=……….
   A. 3:2 B. 2:3 C. 4:3 D. 3:4 E. None of them
4. The cost of 40 pens is k. 360 and the cost of 30 pencils is k. 90. The ratio of the cost of a
   pen to that of a pencil is
   A. 1:3 B. 1:4 C. 3:1 D. 4:1 E. 16:3
5. The ratio of the area of a circle of radius 7 cm to the area of a circle of radius 14 cm is
   A. 1:2 B. 2:3 C. 3:5 D. 4:9 E. 1:4
6. If the ratio of the areas of two circles is 49:25 , then the ratio of the diameters of these
   circles is