STD - 7 MATHS ENGLISH MEDIUM CHAPTER - 4 EXERCISE 4.1 SOLUTION

 

1.                                  

                                                Direct and Inverse Proportion

ee                                     Exercise 4.1

1.          Fill in the blanks

 

1.    If the cost of 8 apples is ` 56 then the cost of 12 apples is__

2.    If the weight of one fruit box is 3(1/2) kg, then the weight of 6 such      boxes is ______.

3.     A car travels 60 km with 3 liters of petrol. If the car has to cover the distance of 200 km, it requires    liters of petrol.

4.     If 7 m cloth costs  294, then the cost of 5 m of cloth is____

5.     If a machine in a cool drinks factory fills 600 bottles in 5 hrs, then it will  fill______ bottles in 3 hours.

2.        Say True or False

1.        Distance travelled by a bus and time taken are in direct proportion.

2.       Expenditure of a family to number of members of the family are in      direct         proportion.         

3.       Number of students in a hostel and consumption of food are not in direct       proportion.

4.        If Mallika walks 1 km in 20 minutes, then she can cover 3 km in 1 hour.

5.      If 12 men can dig a pond in 8 days, then 18 men can dig it in 6 days. 

 

Objective type questions

1.        If the cost of 3 books is ` 90, then find the cost of 12 books.

(i) ` 300                  (ii) ` 320                 (iii) ` 360                (iv) ` 400

2.        If Mani buys 5kg of potatoes for ` 75 then he can buy            kg of potatoes for ` 105.

(i) 6                        (ii) 7                       (iii) 8                       (iv) 5

3.        35 cycles were produced in 5 days by a company then______ cycles will be produced in 21 days.

 (i) 150                     (ii) 70                      (iii) 100                   (iv) 147

4.        An aircraft can accommodate 280 people in 2 trips. It can take ______trips to take 1400 people

(i) 8                        (ii) 10                      (iii) 9                       (iv) 12

5.        Suppose 3 kg. of sugar is used to prepare sweets for 50 members, then_____ kg. of sugar is required for 150 members.

(i) 9                        (ii) 10                      (iii) 15                     (iv) 6                               

                                   Exercise 4.1

1.        A dozen bananas costs ` 20. What is the price of 48 bananas?

2.        A group of 21 students paid ` 840 as the entry fee for a magic show. How many students entered the magic show if the total amount paid was ` 1,680?

3.        A birthday party is arranged in third floor of a hotel. 120 people take 8 trips in a lift to go to the party hall. If 12 trips were made how many people would have attended the party?

4.        The shadow of a pole with the height of 8 m is 6m. If the shadow of another pole measured at the same time is 30m, find the height of the pole?

5.        A postman can sort out 738 letters in 6 hours. How many letters can be sorted in   9 hours?

6.        If half a meter of cloth costs ` 15. Find the cost of 8(1/3) meters of the same cloth.

7.        The weight of 72 books is 9kg. what is the weight of 40 such books? (using unitary method)

8.        Thamarai pays ` 7500 as rent for 3 months. With the same rate how much does she have to pay for 1 year? (using unitary method).

9.        If 30 men can reap a field in 15 days, then in how many days can 20 men reap the same field? (using unitary method).

10.      Valli purchases 10 pens for ` 180 and Kamala buys 8 pens for ` 96. Can you say who bought the pen cheaper? (using unitary method).

11.      A motorbike requires 2 litres of petrol to cover 100 kilometers. How many liters of   petrol will be required to cover 250 kilometers? (using unitary method)