If `1/a :1/b :1/c=3:4:5,` then `a : b : c` (a) `5:4:3` (b) `20 : 15 : 12` (c) `9: 12 : 15` (d) `12 : 15 : 20`

If (1)/(a):(1)/(b):(1)/(c)=3:4:5, then a:b:c5:4:3(b)20:15:12^(c):12:15(d)12:15:20

3, 7, 6, 5, 9, 3, 12, 1, 15, (......) (a) 18 (b) 13 (c) -1 (d) 3

Add : 3b - 7c + 10, 5c - 2b - 15, 15 + 12c + b

Three numbers are in the ratio 1:2:3 and their H.C.F.is 12. The numbers are (a) 4,8 ,12 (b) 5,10,15 (c) 10,20,30 (d) 12 ,24,36

The coefficient of t^4 in ((1-t^6)/(1-t))^3 (a) 18 (b) 12 (c) 9 (d) 15

The coefficient of t^4 in ((1-t^6)/(1-t))^3 (a) 18 (b) 12 (c) 9 (d) 15

The coefficient of t^4 in ((1-t^6)/(1-t))^3 (a) 18 (b) 12 (c) 9 (d) 15

If A = {3, 6, 9, 12 , 15 , 18 , 21} , B = { 4, 8, 12 ,16 , 20 } , C = { 2, 4, 6, 8, 10 , 12 , 14 , 16 } , D = {5, 10 , 15 , 20 } ; find(i) A - B (ii) A - C (iii) A - D

The coefficient of t^(4) in ((1-t^(6))/(1-t))^(3) (a) 18 (b) 12( c) 9(d)15

Let A={3,6, 12 , 15 , 18 , 21},\ B={4,8, 12 , 16 , 20},\ C={2,4,6,8, 10 , 12 , 14 , 16}a n d\ D={5, 10 , 15 , 20} . Find: B-C