EXERCISE 11(B)
1. The monthly salary of a person is 12,000 and his monthly expenditure is 8,500. Find
the ratio of his :
(i) salary to expenditure
(ii) expenditure to savings
(iii) savings to salary
2.
The strength of a class is 65, including 30 girls. Find the ratio of the number of:
(i) girls to boys
(ii) boys to the whole class
(iii) the whole class to girls.
3. The weekly expenses of a boy have increased from 1,500 to 2,250. Find the ratio of
(i) increase in expenses to original expenses.
(ii) original expenses to increased expenses.
(iii) increased expenses to increase in expenses.
Concise MATHEMATICS Middle School
102
Answers
1.
Part 1 ... 24:17 ans
Part 2 .....17/7'
Part3......7:24
Answer:
1. (i) salary/expenditure = 12000/8500 =24/17 (ANS= 24:17)
(ii)salary = 12000, expenditure= 8500,
saving = salary - expenditure
= 12000- 8500
= 3500
expenditure/saving = 8500/3500= 17/7
(Ans. =17:7)
(III) saving/ salary = 3500/12000 = 7/24
( ANS. = 7:24)
2. total students= 65, girls = 30,
boys = 65-30
= 35
(I) girls/ boys = 30/35= 6/7 = 6:7
ii boys/ whole class = 35/65 = 7/ 13= 7:13
III whole class / girls = 65/30 = 13/6 = 13:6
3. original expenses = 1500
new experience = 2250
increase in exp. = 2250-1500 = 750
(I)increase in exp./ original exp. = 750/1500= 1/2= 1:2
(ii) original exp/ increase exp = 1500/750 =2/1= 2:1
(III) increased expenses/ increase in exp. = 2250/750 = 3/1= 3:1