在含鹽5%的鹽水中,鹽與水的質(zhì)量比,寫成最簡整數(shù)比是________,比值是________.
1:19
分析:(1)根據(jù)“含鹽5%的鹽水”,把鹽的質(zhì)量看作5份,鹽水的質(zhì)量就是100份,則水的質(zhì)量是(100-5)份,由此用鹽的份數(shù)比水的份數(shù),進而化簡成最簡比;
(2)用最簡比的前項除以后項即得比值.
解答:(1)鹽的質(zhì)量看作5份,鹽水的質(zhì)量就是100份,
則水的質(zhì)量份數(shù):100-5=95(份),
鹽與水的質(zhì)量比:5份:95分=1:19;
(2)5份:95分,
=1:19,
=1÷19,
=
;
故答案為:1:19,
.
點評:關(guān)鍵是把百分數(shù)轉(zhuǎn)化為份數(shù),找準鹽與水的份數(shù),寫出對應(yīng)比,再化簡成最簡比,注意:最簡比是比的前后項是互質(zhì)數(shù)的比.