Question

sum of ages of brother and sister is 45. five years ago three times the age of sister was five more than two times the age of brother at that time. find present ages of brother at that time. find present ages of brother and sister respectively?/

a) 22, 23
b) 25, 20
c) 30, 15
d) 18, 27

Answer 1

Answer:

sum of ages=45 yrs

Brother = x yrs

sister = 45-x yrs

5 yrs ago

Brother = x-5

Sister=45-x-5=40-x

3(40-x) = 2(x-5) +5

120-3x=2x-10+5

120-3x=2x-5

125 = 5x

x = 125/5=25

present age of Brother x=25 yrs

..... sister 45-x=20yrs

Answer 2

Let present age of brother be "M" years.

Sum of ages of brother and sister is 45 years.

So, age of sister = (45 - M) years

Five years ago three times the age of sister was five more than two times the age of brother at that time.

Now,

• Age of brother = (M - 5) years
• Age of sister = (45 - M - 5) = (40 - M) years

According to question

=> 3(40 - M) = 2(M - 5) + 5

=> 120 - 3M = 2M - 10 + 5

=> 120 - 3M = 2M - 5

=> 120 + 5 = 2M + 3M

=> 125 = 5M

=> M = 25

∴ Present age of brother = M

=> 25 years

∴ Present age of sister = 45 - M

=> 45 - 25

=> 20 years

•°• Option b) 25, 20