Let N be what he started with
After he gave1/3 of his coins to Clark and 1/3 of the remaining coins to Lois we have
After giving (1/3) to Clark, he had (2/3)N left
After giving (1/3) of these to Lois, we have
(2/3)[(2/3)N] = 144
(4/9) N = 144
N = 144 * 9 / 4 = 324
After giving (1/3) of these to Clark he had 216 left
He gave (1/3) of these to Lois = 216 / 3 = 72