Question

Mandar is younger by 10 years than one-fourth of his grandfather's age. Mandar is younger by 3 years than one-seventh of his grandmother's age. Mandar's grandfather is 60 years old. What is his grandmother's age?

Answer 1

ANSWER:

• The age of Mandar's grandmother = 56.

GIVEN:

• Mandar is younger by 10 years than one-fourth of his grandfather's age.

• Mandar is younger by 3 years than one-seventh of his grandmother's age.

• Mandar's grandfather is 60 years old.

TO FIND:

• The age of Mandar's grandmother.

EXPLANATION:

Let the age of Mandar's grandmother be x and Mandhar's age be y.

y = (1/4 × 60) - 10

y = 15 - 10

y = 5

Mandar is 5 years old.

y = (1/7 × x) - 3

Substitute y = 5

5 = (1/7 × x) - 3

8 = x/7

x = 56

Hence Mandar's grandmother is 56 years old.

VERIFICATION:

Mandar is younger by 10 years than one-fourth of his grandfather's age.

5 = (1/4 × 60) - 10

5 = 15 - 10

5 = 5

Mandar is younger by 3 years than one-seventh of his grandmother's age.

5 = (1/7 × 56) - 3

5 = 8 - 3

5 = 5

HENCE VERIFIED.