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

If a/b=7/3 then find the value of (5a+3b)/(5a-3b) and (5a^2+3b^2)/(5a^2-3b^2)

If a=1,b=8,c=15, find the value of b^2-4ac.

If (15a^2+4b^2)/(15a^2-4b^2) = 47/7 then find the value of the ratio : (b^3-2a^3)/(b^3+2a^3)

Choose the correct alternative answer for each of the following question. If a:b =5:3 , then what is the value of (3a +2b) :(3a-2b) ?

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