Time is taken by Raman to complete one round of field = 18 min.
Time is taken by Anupriya to complete one round of field = 12 min.
They will meet again at staring point = L.C.M. (18, 12)
Prime factors of 18 and 12
18 = 2 × 3 × 3 = 2 × 32
12 = 2 × 2 × 3 = 22 × 3
L.C.M. (18, 12) = 22 × 32 = 4 × 9 = 36
Hence, Raman and Anupriya will be meet after 36 minute at starting point.