1、2+5+8+……+194=(2+194)x65÷ 2
4+7+10+……+196=(4+196)x65÷ 2
原式=【(2+194)x65÷ 2】÷ 【(4+196)x65÷ 2】=196÷ 200=0.98
2、166又1/20除以23
=(161+5+1/20)÷23
=161÷23+101/20÷23
=7+101/460
=7又 101/460
3、(362+548×361)÷(362×548-186)
=(361×549+1)÷(362×548+362-548)
=(361×549+1)÷(361×548+362)
=(361×548+361+1)÷(361×548+362)
=1