甲數(shù)是乙數(shù)的60%,丙數(shù)是甲數(shù)的30%,問丙數(shù)比乙數(shù)少________%.
82
分析:設(shè)乙數(shù)是1,先把乙數(shù)看成單位“1”,甲數(shù)是乙數(shù)的60%,由此用乘法求出甲數(shù);
再把甲數(shù)看成單位“1”,丙數(shù)是甲數(shù)的30%,由此用乘法求出丙數(shù);
然后再求出乙數(shù)和丙數(shù)的差,再用差除以乙數(shù)即可.
解答:設(shè)乙數(shù)是1,那么甲數(shù)是:
1×60%=0.6;
丙數(shù)是:
0.6×30%=0.18;
(1-0.18)÷1,
=0.82÷1,
=82%;
故答案為:82.
點評:解答此題的關(guān)鍵是分清兩個單位“1”的區(qū)別,找清各自以誰為標準,再把數(shù)據(jù)設(shè)出,然后根據(jù)基本的數(shù)量關(guān)系求解.