lf half of a number is 30,then three-quarters of it is____.A.forty B.forty-five C.sixty D.fifty
问题描述:
lf half of a number is 30,then three-quarters of it is____.A.forty B.forty-five C.sixty D.fifty
答
选B
如果一个数的一半是30,那么这个数的四分之三是(?)
设这个数是 x
则1/2 * x =30
得x= 60
那么3/4 * x =3/4 *60 = 45