Question
Twelve years ago, the average age of a family having
four members (father, mother, son and daughter) is (y-2) years. The ratio between the present ages of son and daughter is 3:5 respectively. Five years hence, the age of father is nine years more than double the age of daughter. If the present age of father is 64 years, then find out the age of mother 18 years hence.Solution
The ratio between the present ages of son and daughter is 3:5 respectively.
Let’s assume the present ages of son and daughter are ‘3z‘ and ‘5z‘ respectively.
Five years hence, the age of father is nine years more than double the age of daughter.
So five years hence, the age of daughter = (5z+5)
Five years hence, the age of father = 2(5z+5)+9
= 10z+10+9
= 10z+19
Present age of father = 10z+19-5
= 10z+14
If the present age of father is 64 years
10z+14 = 64
10z = 64-14
10z = 50
z = 5
present age of son = 3z = 3x5 = 15 years
present age of daughter = 5z = 5x5 = 25 years
Twelve years ago, the average age of a family having four members (father, mother, son and daughter) is (y-2) years.
Twelve years ago, the age of father + Twelve years ago, the age of mother + Twelve years ago, the age of son + Twelve years ago, the age of daughter = 4(y-2)
(64-12)+Twelve years ago, the age of mother+(15-12)+(25-12) = 4(y-2)
52+Twelve years ago, the age of mother+3+13 = 4(y-2)
Here the information about two things which are the age of the mother and the value of ‘y’ are unknown. So we cannot determine the age of mother 18 years hence from the given information.
The radius of a circle is 14 cm, and the angle subtended by a sector at the center of the circle is 120°. Find the area of the sector.
The diagonals of a rhombus are 16 cm and 12 cm. Find the area of the rhombus.
A rectangle has a length that is 4 cm more than its width. If the perimeter of the rectangle is 32 cm, find the dimensions of the rectangle.
Two trains are moving in opposite directions at speeds of 72 km/hr and 54 km/hr. If they cross each other in 15 seconds, find the length of the faster t...
An inlet pipe can fill a cistern in 25 minutes when working alone. However, due to a leak, the fully filled cistern would empty in 87.5 minutes. If the ...
Which tab is NOT included in MS-PowerPoint?
Which of the following graphical models represents the relationships between entity sets in a database?
A spherical balloon is being inflated such that its radius is increasing at a rate of 2 cm per second. After 5 seconds, find the volume of the balloon. ...
A sphere is inscribed in a cylinder. The radius of the cylinder is 7 cm. What is the volume of the sphere?