CM.RP.CB6.LU4.L3 (Ratio &proportions)

The perimeetr of a rectangular hall is 160 m ,Its length and breadth are in the ratio 3:5 .The area of the hall is (a)   sq.m.

Answer explanation

Let length = 3x and

and breadth= 5 x

Perimeter=2(3x+5x)

Given perimeter = 160 m

160 = 6x + 10 x

160 = 16 x

x = 160 /16

x = 10

Length = 3 x 10 = 30 m

Breadth = 5 x 10 = 50 m

Area = 30 x 50 =

1500 sq.m

Sangeetha and Ayisha started a designer store.They decided to share the profit int he ratio of their investment.Ayisha invested Rs. 9000 and her share of profit was Rs.3000.If the total profit was Rs.7500, Sangeetha's investment is Rs. (a)   .

Ramesh made a profit of Rs. 4500 after investing Rs. 80,000. Salim made a profit of Rs. 8100 investing Rs. 144000 in his business. Which of them has a better profit ratio with respect to their investments?

Answer explanation

Profit ratio =

Profit /Investment

Find Profit ratio of each person and find which ratio is larger.

Sheela bought some rose plants and sunflower plants. There was 35 more rose plants than sunflower plants. If the ratio of rose to sunflower plants is 8:3 . Find the number of rose plants.

(a)  

A man runs 10 km in half an hour. How many Km does he run in 45 mins?

(a)  

The ratio between men and women in an office is 5:7, If there are 42 women, find the total number of men in the office.

(a)  

Answer explanation

Given ,

Ratio Men: women = 5: 7

number of women = 42.

If total number of people in each part is p

the office has 7 parts of women ,

So number of women = 7 p

So, 7 p= 42 .

p = 6

So there are 6 member in each part.

There are 5 parts of men .

So, number of men

= 5 p = 5 x 6 = 30 men

The monthly expenses have increased from 350/- to 500/- .

Find the ratio of increase in expense to original expense (in simplest form)

Mathematical Equivalence

ON

Answer explanation

Original Expense = 350/-

New expense = 500/-

Increase in expense = 500-350

= 150/-

Ratiof increase in expense to original expense = 150/350

=3/7

Mathematical Equivalence

ON

Answer explanation

a : b = 2: 5

If total number of items in each part is p,

In 2 parts, there will be 2p items. So, a = 2p

In 5 parts, there will be 5p,

b = 5p

Now, 3a+2b : 4a+b is asked

We found that a = 2p ,

so 3a= 3 x 2p = 6 p

b = 5p , so 2b = 2 x 5p = 10p.

4a = 4 x 2p = 8p

b = 5p

Finally, 3a + 2b : 4a + b

= 6p+10p : 8p + 5p

= 16p : 13P

= 16:13

Divide 1400/- among Meena, Geeta and Sumit such that Meena gets twice of what Geeta gets and Sumit gets half of what Geeta gets. Geeta gets _____

Mathematical Equivalence

ON

Answer explanation

Total 1400/-

Meena:Geeta:Sumit

If Geeta gets p ,

Meena gets 2p and Sumit gets 0.5 p

So: Meena : Geeta : Sumit

= 2p : p : 0.5p

2p + p + 0.5p = 1400

3.5 p = 1400

p =1400/3.5

p= 400