標題:
maths S.1 急...THX
發問:
1.A water tank leaks 4L water every minute. Find the change in capacity of water in the water tank on 12 minute.2.If a positive number represents above sea level, and a negative number represents below sea level. (a)Use a directed number to represent the following situations. (i)15 m above sea... 顯示更多 1.A water tank leaks 4L water every minute. Find the change in capacity of water in the water tank on 12 minute. 2.If a positive number represents above sea level, and a negative number represents below sea level. (a)Use a directed number to represent the following situations. (i)15 m above sea level (ii)10 m below sea level. (b)Describe the meaning of ‘-21 m’ 3.Find the value of the expression (-101) + 102 + (-103) + 104 +…+ (-199) + 200 4.If the sum of three consecutive odd number is 81, find the largest odd number 5.After mixing 240 g of sugar solution with 45% concentration ( i.e. 45 g sugar per 100 g of sugar solution ) with 260 g of sugar solution with 35% concentration, find the percentage in concentration of the sugar solution. 6.40% of the students in S1A failed in a physical test. They had to sit for another test in which 62.5% of them failed again. (a)Find the percentage of students who failed in both tests. (b)If 10 students failed in both tests, how many students are there in S1A? 7.If 25% of a steel pipe is cut, then the length of steel pipe remaining is 2.1 m. If 85% of it is cut, what is the length of pipe remaining? 8.Among all visitors at the Nini Park one day, 54% of male visitors and 70% of female visitors are local people. If the number of non-local male and demale visitors is 598 and 435 respectively on that day, how many visitors are there at the Park on that day? 9.Mr Lee paid the electricity bill for $560 in September which is $140 less than in August Find the percentage decrease in the electricity bill. 更新: 請比過程 唔係當作棄
此文章來自奇摩知識+如有不便請留言告知
最佳解答:
1.A water tank leaks 4L water every minute. Find the change in capacity of water in the water tank on 12 minute. 4x12=48L 2.If a positive number represents above sea level, and a negative number represents below sea level. (a)Use a directed number to represent the following situations. (i)15 m above sea level +15m (ii)10 m below sea level. -10m (b)Describe the meaning of ‘-21 m’ 21m below sea level 3.Find the value of the expression (-101) + 102 + (-103) + 104 +…+ (-199) + 200 because from 101 to 200, there are 100 numbers.and sum of 2 consecutive number is +1. then we have, (-101+102)+(-103+104)+...+(-199+200) =1+ 1+ 1...+1 =50 4.If the sum of three consecutive odd number is 81, find the largest odd number assume the middle number is p, then p-2+p+p+2=81 3p=81 p=27 so, the largest odd number is 29 5.After mixing 240 g of sugar solution with 45% concentration ( i.e. 45 g sugar per 100 g of sugar solution ) with 260 g of sugar solution with 35% concentration, find the percentage in concentration of the sugar solution. sugar contain in 240g solution=240x0.45=108g sugar contain in 260g solution=260x0.35=91g so the concentration of sugar the mix solution: (91+108)/(240+260)x100% =199/500=39.8% 6.40% of the students in S1A failed in a physical test. They had to sit for another test in which 62.5% of them failed again. (a)Find the percentage of students who failed in both tests. 6.4%x62.5%=4% (b)If 10 students failed in both tests, how many students are there in S1A? 10/4%=250 7.If 25% of a steel pipe is cut, then the length of steel pipe remaining is 2.1 m. If 85% of it is cut, what is the length of pipe remaining? 2.1/(1-25%)x(1-85%)=0.42m 2010-07-23 14:36:10 補充： 8.Among all visitors at the Nini Park one day, 54% of male visitors and 70% of female visitors are local people. If the number of non-local male and demale visitors is 598 and 435 respectively on that day, how many visitors are there at the Park on that day? 598/(1-54%)+435/(1-70%)=1300+1450=2750 2010-07-23 14:37:54 補充： 9. august paid=560+140=700 % decrease=140/700=20%
其他解答:
1.48 2.21 3.0 4.81 5.35 6.90人 7.15 8.435 9.140。
留言列表
