標題:
Maths(10分的)
此文章來自奇摩知識+如有不便請留言告知
發問:
幫我記算這兩題1.A 2-digit number is divisible by both 2 and 5 . Half this number is less than 6 times the tens digit of the number by 4. Find this 2-digit number.2.there are some chickens and rabbits in a cage. 1/3 of the rabbits were born to have 3 legs. If the total number of heads is 35 and the total number of legs... 顯示更多 幫我記算這兩題 1.A 2-digit number is divisible by both 2 and 5 . Half this number is less than 6 times the tens digit of the number by 4. Find this 2-digit number. 2.there are some chickens and rabbits in a cage. 1/3 of the rabbits were born to have 3 legs. If the total number of heads is 35 and the total number of legs is 90,find the number of a) chickens, b) rabbits with 4 legs. please help me to solve this two questions!!!!!!!!!!!!!!!!!! Thanks!
最佳解答:
1)我答過...http://hk.knowledge.yahoo.com/question/?qid=7007102704483 二位數可被2和5整除...個位一定是0 設這個數的十位數為y....這個數便是10y 10y/2=6y-4 5y=6y-4 y=4 這個2位數是40 2a let chicken be y隻 and then rabbit 係z隻 y+z=35.....(1) 2y+3x(z)x1/3+(2z/3)x4=90 2y+z+8z/3=90....(2) in(1)啦 z=35-y....(3) sub (3) into (2) 2y+(35-y)+8(35-y)/3=90 6y+3(35-y)+8(35-y)=270 6y+105-3y+280-8y=270 -5y=270--385 y=23 有23隻雞雞.. b..rabbits的數目有35-23=12隻 1/3得三隻腳...即2/3有4隻腳...(點解會有3隻腳ge rabbits !!!!=口=) 有4隻腳rabbits:12x2/3=8隻
其他解答:
留言列表
