甲比乙多25%,乙比甲少________%,甲比乙是________.
20 5:4
分析:甲比乙多25%,把乙數(shù)看作單位“1”,則甲數(shù)為(1+25%),進(jìn)而求出甲數(shù)與乙數(shù)的比;求乙比甲少百分之幾,是把甲數(shù)看作單位“1”,根據(jù)“(大數(shù)-小數(shù))÷單位“1”的量”解答即可.
解答:(1+25%-1)÷(1+25%)
=0.25÷1.25,
=0.2,
=20%;
(1+25%):1,
=1.25:1,
=(1.25÷0.25):(1÷0.25),
=5:4;
故答案為:20,5:4.
點評:此題屬于求一個數(shù)比另一個數(shù)多(或少)百分之幾,解答關(guān)鍵是把被比的數(shù)看作單位“1”(作除數(shù)),用除法解答.