Maths_11112 @ 快遞百科

標題:

Maths

發問:

7.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.8.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 in 35 and the total number of legs... 顯示更多 7.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. 8.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 in 35 and the total number of legs is 90,find the number of (a)chickens, (b)rabbits with 4 legs.

最佳解答:

7. the 2-digit number is divisible by both 2 and 5, i.e. it is divisible by 10 so the last digit should be 0 let the tens digit be x then the number = 10x 10x/2 + 4 = 6x you solve it by yourself, the answer should be 40. 8. let the number of chicken be x, then the number of rabbits will be 35-x (because there are 35 heads in total) 2x (chickens have 2 legs) + (1/3)(35-x)(3) (one-third of rabbits have 3 legs) +(2/3)(35-x)(4) (the rest of the rabbits have 4 legs) = 90 you solve it by yourself the answer is 23 chickens and 8 rabbits with 4 legs