NCTB Class 6 Math Chapter Two Exercise 2.3 Solution

NCTB Class 6 Math Chapter Two Exercise 2.3 Solution by Math Expert. Bangladesh Board Class 6 Math Solution Chapter 2  Ratio’s & Percentages Exercise 2.3 Solution.

Board	NCTB
Class	6
Subject	Mathematics
Chapter	2
Chapter Name	Ratio’s & Percentages
Exercise	2.3 Solution

 

Exercise:- 2.3

(1) In the following chart, match the expression of the left to that of the right.

(a) Ratio	(a) %
(b) Unit ratio	(b) a fraction
(c) Symbol of percentage	(c) 1:5
(d) Ratio in greater inequality	(d) 9:9
(e) Ratio in less inequality	(e) 7:3

 

Solution:-     a–b

b–d

c–d

(d)–c

(e)–c

(2) What is ratio?

Solution:- Ratio is (a) A fraction.

(3) Which is the equivalent ratio of 2:5 of the followings?

Solution:- The equivalent ratio of 2:5 is— (c) 4:10

(4) Which of the following is the compound ratio of 3:4 and 4:5?

Solution:-  The compound ratio of 3:4 and is – (b) 12:20

(5) If the ratio 3:20 is expressed into percentage, which of the following is correct?

Solution:-

3:20 = 3/20 x100

= 15

Answer:- (c)15%

(6) 1% of 200 centimetre is –

Solution:- 15 of 200cm is – (c) 2cm

(7) In the ratio 1:5

Solution:- In the ratio 1:5 – (d) (i), (ii), (iii) Correct Answer.

(8) Of 100 boys and girls, if 60% is girls

Solution:- The correct answer is – (d) (i), (ii), (iii)

(9) What is the ratio of the marked part and the whole part of the diagram?

Solution:- Ratio the marked part and the whole part of the diagram is – (a) 1:4

(10) What is the area of the greatest square of the diagram?

Solution:- Area f greatest square of diagram is – (d) 4 square meter.

(11) How many men’s work can 9 boys do?

Solution:- (b) 6 persons.

(12) What amount of money would each boy get if 3 boys would do the work?

Solution:- (d) 300 Taka [900/3 = 300]

(13) Yousuf have obtained 70% of marks. What marks has yousuf obtained if the total marks of examination are 700?

Solution:- Total marks = 700

Yousuf obtained = 70% of total marks.

Therefore, He obtained = 700x 700/100

(b) = 490 Answer.

(14) What is the price of 5kgs of rice if the price of 8kgs of rice is TK.168?

Solution:- Price of 8kg’s rice = 168

Therefore, price of 1kg’s rice = 168/8

Therefore, price of 5kg’s rice = 168×5/5

= 21×5

= 105kg.

 (15) What will be the price of 15kgs of rice if the price of 7kgs of rice is TK.280?

Solution:- Price of 7kgs rice = TK.280

Therefore, price of 1kg’d rice = 280/7

Therefore, price of 15kg’s rice = 280×15/7

= 40×15

= 600Rs/-.

(16) In hostel there was food stored for 50 students for 15days. For how many days will 25students be served by that quantity of food?

Solution:- Food stored for 50 students for 15days

Therefore, food stored for 25 students for 15/50×25

= 7.5 days.

(17) A shopkeeper by investing TK.9000 makes a profit of TK.450 daily. How much money is to be invested if he wants to make a profit of TK.600 daily?

Solution:- For, 450 profit investing TK.9000

Therefore, 1 profit investing TK.900/450

Therefore, 600 profit investing (9000/450×600)

= 1200 Rs/- to be invested.

(18) 10 persons can be served for 27days with 120kgs of rice. How many kgs. of rice are needed to serve the same number of persons for 45days?

Solution:- 27 days with 120kgs of rice

Therefore, 1 days with 120/27

Therefore, 45 days with 120×45/27

= 200kgs of rice.

(19) There are 2 quintals of rice for 15 students for 30days. How many days will be required to serve 20 students with the same quantity of rice?

Solution:- 2 quintal rice for 15 students for 30 days

2 quintal for 20 students for = 30×15/20

= 45/2

= 22 1/2days.

(20) There are 25 students living in a hostel. They need 625 gallons of water in a week. How many students will be able to fulfil their needs if there are 900 gallons of water?

Solution:- 625 gallons water need for 25 students .

1 gallons water need for 25/625 students

900 gallons water need for = 25×900/625 students

= 36 students.

(21) 9 workers can do a piece of work in 18days. In how many days can 18 workers do that piece of work?

Solution:- 9 workers can do a piece of work 18 days.

Therefore, 1 workers can do a piece of work 18×9

Therefore, 18 workers can do a piece of work 18×9/18

= 9 days Answer.

(22) 360 workers can construct an embankment in 25days. How many extra workers are needed to finish the constructions in 18days.

Solution:- In 25 days embankment construct 360 workers

Therefore, 1days embankment construct 360×25 workers

Therefore, 18 days embankment construct 360×25/18 workers

= 500 workers.

Therefore, Extra worker needed

= (500-360)

= 140 workers. Answer.

(23) By working 6 hours daily 25 persons can do a piece of work in 8 days. In how many kilometres does the run in 6days and what is his speed?

Solution:- 25 persons working 6 hours daily, days

Therefore, (6×8) = 48 hours total

25 persons do work 6hr daily 8 hours

10 persons do work 6hr daily 8x25x6/10×6

= 20 days.

(24) A school students crosses 10km. in 2 hours by cycling from his house to school. How many kilometres does he run in 6 days and what is his speed?

Solution:- Student, in 2hr crosses 10km

Therefore, in 6days

= 6×12

= 10/2×12

= 60kmAnswer.

His speed = 60/12

= 5km/hr. Answer.

(25) Walking 10hours daily Rabin crosses 480km in 12days. In how many days can he cross 360km walking 9 hours daily?

Solution:- Rabin 12×10 =120hr crosses

Walking 10hr daily in 12 days crosses 480km

Therefore, Walking 1hr daily in 1 days crosses 480km

Speed = 480/10×12

= 4km/hr.

360km distance cross by walking 9hrs daily days required = 360/4×9

= 10days. Answer.

(26) Jalal crosses 9km path in each 3 hours does he need to cross 36km?

Solution:- Jalal speed = 9/3 km/hr

= 3km/hr

To cross 36 km time taken

= 36/3

= 12days (Answer)

(27) 6 workers can reap crops of a field in 28days. In how many days will 24 workers reap the crops of that field?

6 workers can reap crops of field in 28 days

Therefore, 1 workers can reap crops of a field in 28×6/24

= 7 day (Answer)

(28) 2 men can do the same amount of work that 3 boys can do. 4 men and 10 boys together can do a piece of work in 21 days. In how many days will 6 men and 15 boys do that work?

4 men and 10 boys together can do work in 21 days

Therefore, 1 men and 10 boys together can do work in 21x4x10

Therefore, 6 men and 15 boys together can do works in 21x4x10/6×15 days

=21 days (Answer)