For ball `A`
` u_(1) = 0.3 ms _(-1) , a_(1) = - 2 ms^(-2) , s_(1) = x , t_(1) = t `
`:. s _(1) = u_(1)t_(1) + (1)/(2) a_(1) t _(1)^(2)`
` x = 0.3 t - t^(2)` ....(i)
For ball ` B`
` u_(2) = 0.2 ms^(-1) , a_(2) = 2 ms^(-2) , s_(2) = 4 -x, t_(2) = t`
`:. s_(2) = u_(2) t_(2) + (1)/(2) a_(2) t_(2)^(2)`
` 4 - x = 0.2 t + t^(2)` ....(2)
From `(1)` and `(2) t = 8 sec`