Answer
Infinite number of solutions.
Work Step by Step
$Since\:the\:system\:has\:a\:unique\:solution,\:we\:know\:that\:none\:of\:the\:equations\:is\:a\:multiple\:of\:another\:and\:there\:are\:no\:inconsistencies\:in\:any\:of\:the\:equations.\:Therefore,\:when\:using\:only\:two\:of\:the\:three\:equations,\:we\:have\:more\:variables\:than\:equations.\:As\:a\:result,\:by\:Theorem\:1.1,\:this\:states\:that\:if\:there\:are\:more\:variables\:than\:equations,\:there\:will\:be\:an\:infinite\:number\:of\:solutions.$