If `a:b = 2:1` and `b:c = 4:1`, then find `a:c`.

If a:b=3:1 and b:c=5:1 , then find the value of ((a^3)/(15b^2c))^3

If a:b=3:1 and b:c=5:1 , then find the value of a^2/(7bc)

If a:b=7:8 and b:c=12:7 then find a:c in the simplest form.

If tan A=(a)/(a+1) and tan B=(1)/(2a+1) then find the value of A+B=................. A) 0 B) pi/2 C) pi/3 D) pi/4

If A = [[1,1],[1,2]] , B = [[4,1],[3,1]] and C = [[24,7],[31,9]] then find the matrix X , such that AXB = C .