问题1：找到以下比率
(a)自行车的速度为每小时15公里，而踏板车的速度为每小时30公里。
(b)5 m至10 km(c)50帕兹至₹5
解决方案：
(a) Speed of a cycle 15 km per hour to the speed of scooter 30 km per hour
Ratio = Speed of Cycle : Speed of Scooter
= 15 km per hour : 30 km per hour
= 15/30 = 1/2
So, the ratio is 1 : 2
(b) 5 m to 10 km
Fist of all, the units of both quantities must be same
So, Convert 10 km into m
Since 1 km = 1000 m
Hence, 10 km = 10,000 m
Ratio = 5 m : 10,000 m
= 5/10000 = 1/2000
So, the ratio is 1 : 2000
(c) 50 paise to ₹ 5
Fist of all, the units of both quantities must be same
Convert ₹ 5 into paise
Since ₹ 1 = 100 paise
Hence, ₹ 5 = 500 paise
Ratio = 50 paise : 500 paise
= 50/500 = 1/10
So, the ratio is 1 : 10
问题2：将以下比率转换为百分比。
(a)3：4(b)2：3
解决方案：
In order to convert ratios to the percentage, we must multiply it with 100
(a) 3 : 4
3 : 4 = (3/4) X 100 = 75%
(b) 2 : 3
2 : 3 = (2/3) X 100 = 66.66% or 67% (approx)
问题3：25名学生中有72％的数学很好。有多少数学不好?
解决方案：
Method 1:
Total students = 25
72% student are good in mathematics, converting it to numbers
Number of students good in mathematics = 72% of 25
= (72/100) X 25
= 18
So number of students who are not good in mathematics = 25 – 18 = 7
So, 7 students are there who don’t like mathematics.
Method 2:
It is given that 72% of 25 students are good in mathematics
So the percentage of people who are not good in mathematics 100% – 72% = 28%
Number of people who are not good in mathematics = 28% of 25 = (28/100) X 25 = 7
So, 7 students are there who don’t like mathematics.
问题4：一支足球队在比赛总数中赢得了10场比赛。如果他们的胜率是40，那么他们总共参加了多少场比赛?
解决方案：
Method 1:
Let us assume that the team played 100 matches and the winning percentage is 40
So, we can say the team won 40 matches out of 100
Also, they won 1 match out of 100/40 matches
Hence, 10 matches were won out of (100/40) X 10 = 25
So, the football team played 25 matches in all.
Method 2:
Let us assume the football team played a total of x matches
The winning percentage is 40% and they won 10 matches
So, we can say
40% of x = 10
(40/100). x = 10
Hence, x = 25
So, the football team played 25 matches in all.
问题5：如果Chameli在花掉75％的钱后还剩600卢比，那么她一开始的钱是多少?
解决方案：
Method 1:
Let us assume that Chameli had ₹ 100 in the beginning
It is given that Chameli had spent 75% of her money
So the money spent by her = 75% of 100 = (75/100) X 100 = ₹75
Hence, money left with her = ₹100 – ₹75 = ₹25
Now,
₹25 are left if she had ₹100 in the beginning
₹1 is left if she had ₹(100/25)
So, ₹600 will be left if she had ₹(100/25) X 600 i.e ₹2400 in the beginning
Hence, Chameli had ₹2400 in the beginning.
Method 2:
Let us assume Chameli had ₹x in the beginning
After spending 75% of x she had ₹ 600 left
So, (100 – 75)% of x = ₹600
= >(25/100). x = 600
Hence, x = ₹2400
Hence, Chameli had ₹2400 in the beginning.
问题6：如果某个城市中60％的人喜欢板球，30％的人喜欢足球，而其余的人喜欢其他游戏，那么有多少人喜欢其他游戏呢?如果总人数是500万，请找到喜欢每种游戏的确切人数。
解决方案：
Total number of people = 50 lakh
60% of people like Cricket
So, the number of people like Cricket = 60% of 50,00,000
= (60/100) X 50,00,000 = 30,00,000
30% of people like Football
So, the number of people like Football = 30% of 50,00,000
= (30/100) X 50,00,000 = 15,00,000
Percentage of people like other games = (100% – 60% – 30%) = 10%
So, the number of people like other games = 10% of 50,00,000
= (10/100) X 50,00,000 = 5,00,000
Hence, 30 lakh people like Cricket, 15 lakh people like Football and 5 lakh people like other games.