Answer
$-Flaw:\:The\:question\:lacks\:clarity\:on\:the\:scale\:of\:measurement\:\left(hours,\:days,\:etc.\right).\\-Rewritten\:Question:\:How\:many\:hours\:did\:you\:study\:for\:this\:examination?$
Work Step by Step
$A\:question\:is\:given\:as\:follows:\\"How\:long\:have\:you\:studied\:for\:this\:examination?"\\We\:are\:supposed\:to\:identify\:the\:flaw\:involved\:in\:$
$the\:above\:question\:and\:rewrite\:the\:question\:following\:$
$the\:survey\:guidelines.\\The\:given\:question\:contains\:a\:word\:how\:long\:which\:$
$can\:be\:measured\:in\:hours,\:days\:etc.\:As\:the\:scale\:of\:$
$measurement\:is\:not\:specified,\:the\:question\:is\:confusing.\\We\:can\:rewrite\:the\:above\:question\:as\:follows:\\"How\:many\:days\:did\:you\:study\:for\:this\:examination?"$
