## Saturday, December 21, 2013

### CBSE Class 8 - Maths - Comparing Quantities (Ex 8.1)

Comparing Quantities
NCERT Chapter (Ex 8.1)

Q1: Find the ratio of the following:

(a)Speed of cycle 15 km per hour to speed of scooter 30 km per hour

Ratio of speed of cycle to speed of scooter

(b) 5m to 10 km

Since 1 Km = 1000 m,

Required Ratio

(c) 50 paise to Rs 5

Since Re 1 = 100 paise ,

Required Ratio

Q2: Convert the following ratios to percentages.

(a)3:4

(b)2:3

Q3: 72% of 25 students are good in mathematics.How many are not good in mathematics?

Since 72% of 25 students are good in mathematics, therefore,

Percentage of students not good in mathematics=(100-72%)=28%

∴ Number of students not good in mathematics

Thus,7 students are not good in mathematics.

Q4: A football team won 10 matches out of the total number of matches they played.If
their win percentage was 40,then how many matches did they play in all?

Let toatal number of matches be x.

Since team won 10 matches and their winning percentage of the team was 40%,So

Thus, the team played 25 matches.

Q5: If Chameli had Rs 600 left after spending 75% of her money,how much did she have in the beginning?

Let amount which she had in beginning be x.

Since she left with Rs 600 after spending 75% of x ,So,

(100-75)% of x = Rs 600

Or, 25% of x = Rs 600

Thus,She had Rs 2400 in the beginning.

Q6: If 60% of people in city like cricket,30% like football and remaining like other
games, then what percent of people like other games? If the total number of people are 50 lakh,
find the exact number who like each type of game.

Percentage of people who like other games =(100-60-30)%

=(100-90)%= 10%

Total number of people= 50 lakh

So number of people who like cricket

Number of people who like football

Number of people who like other games