Book Online Demo
Check Your IQ
Try Test

Courses

Dropper NEET CourseDropper JEE CourseClass - 12 NEET CourseClass - 12 JEE CourseClass - 11 NEET CourseClass - 11 JEE CourseClass - 10 Foundation NEET CourseClass - 10 Foundation JEE CourseClass - 10 CBSE CourseClass - 9 Foundation NEET CourseClass - 9 Foundation JEE CourseClass -9 CBSE CourseClass - 8 CBSE CourseClass - 7 CBSE CourseClass - 6 CBSE Course

Q.

Ten years hence, a man's age will be twice the age of his son. Ten years ago, the man was four times as old as his son. What are their present ages?


see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

The present age of the man is 53 years and the present age of his son is 20 years.

b

The present age of the man is 50 years and the present age of his son is 28 years.

c

The present age of the man is 50 years and the present age of his son is 20 years.

d

The present age of the man is 45 years and the present age of his son is 19 years. 

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Given that, 10 years hence, a man's age will be twice the age of his son.
Ten years ago, the man was four times as old as his son.
Let the man be referred to as A and the boy be referred to as B.
Let the age of A be x years and the age of B be y years.
Five years ago:
A's age = x−5  yrs B's age = y−5  yrs   According to the given information, five years ago, A was thrice as old as B.
x−5 = 3 y−5 ⇒x−5 = 3y−15 ⇒x−3y =−15+5 ⇒x−3y =−10…… 1    Ten years later,
A's age =  x + 10 B's age =  y + 10   According to the given information, ten years later, A shall be twice as old as B.
x+10=2(y+10) ⇒x+10=2y+20 ⇒x−2y=20−10 ⇒x−2y=10......(2)   From equation 1,
x=3y−10  …(3)
Substituting the value of x=3y−10   in the second equation and solving it, we get, x - 2y=10 ⇒ 3y−10  - 2y=10 ⇒y=10+10 ⇒y=20  
Putting the value of y = 20 in equation 3 to find the value of x, we get,
x=3y−10 ⇒x=3 20 −10 ⇒x = 60 −10 ⇒x=50   Hence, the present age of A is 50 years and the present age of B is 20 years.
Thus, option 3 is correct.
 
Watch 3-min video & get full concept clarity
Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Books for IIT JEE
Best Books for NEET
How to Join IIT after 10th
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Books for IIT JEE
Best Books for NEET
How to Join IIT after 10th
whats app icon
Ten years hence, a man's age will be twice the age of his son. Ten years ago, the man was four times as old as his son. What are their present ages?