24.
(2022七上·綦江期中)
閱讀材料∶對于三位自然數(shù)m,各位數(shù)字都不為0,且百位數(shù)字與十位數(shù)字之和恰好能被個(gè)位數(shù)字整除,則稱這個(gè)自然數(shù)m為“開心數(shù)”.例如:437是“開心數(shù)”,因?yàn)?,3,7都不為0,且
, 7能被7整除;724不是“開心數(shù)”, 因?yàn)?img class="mathml" src="http://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E7%3C%2Fmn%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E9%3C%2Fmn%3E%3C%2Fmath%3E" style="max-width:100%;vertical-align: middle;"> , 9不能被4整除.