S.chand class 6 Mathematics Chapter 8 Exercise 8C

 Exercise 8C

Question 1

1. Determine if the following numbers are in proportion.

(i) $3,4,6,7$

(ii) $8,10,16,20$

(iii) $5,7,40,56$

(iv) $18,36,72,144$

Question 2

2. Determine if the following ratios form a proportion.

(i) $90 \mathrm{~cm}$ to $450 \mathrm{~cm}$ and $₹ 7$ to $₹ 35$.

(ii) $35 \mathrm{~mm}$ to $300 \mathrm{~cm}$ and $30 \mathrm{~g}$ to $280 \mathrm{~g}$.

(iii) 12 hours : 30 hours and $8 \mathrm{~km}: 20 \mathrm{~km}$

(iv) $350 \mathrm{~g}: 4 \mathrm{~kg}$ and $75 \mathrm{~cm}$ to $8 \mathrm{~m}$.

Question 3

3. Fill in the blanks of the following so that the four numbers are in proportion.

(i) 50, 75, 30, ___

(ii) 20, __ , 5.2, 1.3

(iii) __ , 63, 3, 21

(iv) 16, 64, __ , 72

4. Fill in the blanks to make the following statements true.

(i) $8 \mathrm{~kg}: __=16 \mathrm{~m}: 12 \mathrm{~m}$

(ii) $__ : 72 \mathrm{~L}=₹ 25: ₹ 36$

(iii) $200 \mathrm{~mL}: 2.5 \mathrm{~L}=__$ : ₹ 50

(iv) 65 girls : 100 girls $=26$ boys : __

5. (i) First, second and third terms of a proportion are 21, 49 and 33 respectively. Find its fourth term:

(ii) First, second and fourth terms of a proportion are $5.2,3.9$ and 3 respectively. Find its third term.

6. The ratio of the length of a rectangular field to its width is $5: 2$. Find its length if the width is 40 metres.

7. In a parking lot, the ratio of the number of bikes to that of cars is $34: 7$. If there are 28 cars in that parking. how many bikes are there?

8. The ratio of the times taken by tap A to fill the bath tub to that taken by tap B is $5: 6$. If tap A takes 36 minutes to fill a bath tub, how long would tap B take to fill the same bath tub?

9. The ratio of the number of girls to that of boys in the school band is $8: 7$. If there are 75 pupils in the band, how many are girls? How many are boys?

10. After selling 85 copies of a book for every 100 copies printed, a publisher finds that 45 copies are left unsold. How many copies were printed?

Multiple Choice Questions (MCQs)

Tick (✔) the correct option.

11.If $a b=36$, which of the following is correct?

(a) $a: 6=b: 6$

(b) $a: 2=b: 18$

(c) $a: 9=4: b$

(d) $4: a=9: b$

12. $25: \ldots \ldots \ldots .=225: 162$. The missing number is

(a) 20

(b) 36

(c) 9

(d) 18