(a) remains (3-i) inches, if i < 3; if i = 3, remains 0 (same as nothing); if i > 3 or i < 0, then the problem makes no sense. (b) remains 3 - (i-5) = 8-i inches, if 5 < i < 8; remains 3 inches, if i = 5; remains 0 inches, if i = 8; if i < 5 OR i > 8, then the problem makes no sense.