8 Views

Question : Directions: Adam who is 20 years old is 4 times as old as Mary. What will be Mary's age when Adam is twice as old as her?

Option 1: 35 years

Option 2: 15 years

Option 3: 30 years

Option 4: 17 years


Team Careers360 25th Jan, 2024
Answer (1)
Team Careers360 27th Jan, 2024

Correct Answer: 15 years


Solution :

Given:
Adam's age = 20 years
Also, Adam's age = 4 × Mary's age
⇒ Mary's age = Adam's age ÷ 4
⇒ Mary's age = 20 ÷ 4 = 5 years.

Let us assume that after A years, Adam's age is twice the Mary's age;
Adam's age after A years = (20 + A) years, and Mary's age after A years = (5 + A) years.
Also, after A years, Adam’s age = 2 × Mary’s age
⇒ (20 + A) = 2(5 + A)
⇒ 20 + A = 10 + 2A
⇒ 20 – 10 = 2A – A
⇒ A = 10 years
Therefore, Mary's age after 10 years will be 15 years, and Adam’s age after 10 years will be 30 years.

So, Mary's age after 10 years will be 15 years. Hence, the second option is correct.

How to crack SSC CHSL

Candidates can download this e-book to give a boost to thier preparation.

Download Now

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
GRE ® Registrations 2024
Apply
Apply for GRE® Test now & save 10% with ApplyShop Gift Card | World's most used Admission Test for Graduate & Professional Schools
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books