If a car covers 2/5th of the total distance with v1 speed and 3/5th distance with v2 then average speed is
(a) 12 𝑣1𝑣2
(b) 𝑣1:𝑣22
(c) 2𝑣1𝑣2𝑣1 : 𝑣2
(d) 5𝑣1𝑣23𝑣1 : 2𝑣2