If `a ,b ,c ,d ,e ,f` are A.M.s between 2 and 12, then find the sum `a+b+c+d+e+fdot`

If a,b,c,d,e, f are A. M's between 2 and 12 , then find a + b + c +d + e +f.

Six persons A, B, C, D, E and F are standing in a circle. B is between F and C. A is between E and D. F is to the left of D. Who is between B and D?

If A = {a,b,c,d}, B = {c,d,e,f} and C= {d,e,f,g} then find AnnB,BnnC and AnnC ,

If D ,\ E ,\ F are the mid points of the side B C ,\ C A and A B respectively of a triangle ABC, write the value of vec A D+ vec B E+ vec C Fdot

In a A B C , D and E are points on the sides A B and A C respectively such that D E B C If A D=4 , A E=8 , D B=x-4 , and E C=3x-19 , find x (ii) If A D=8 c m , A B=12 c m and A E=12 c m , find C E . (iii) If A D=4 c m , D B=4. 5 c m and A E=8 c m , find A C .

In a A B C , D and E are points on A B and A C respectively such that D E||B C . If A D=2. 4 c m ,\ \ A E=3. 2 c m ,\ \ D E=2c m and B C=5c m , find B D and C E .

In a A B C , D and E are points on A B and A C respectively such that D E// B C . If A D=2. 4 c m ,\ \ A E=3. 2 c m ,\ \ D E=2c m and B C=5c m , find B D and C E .