Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

ICSE Class 10 Answered

A man is x² old and his son is x years old. if the man lives to the age of 18x his son then be x² years old. find the present age of the man and the boy.
Asked by dwivedi_anand | 27 Nov, 2018, 04:14: PM
answered-by-expert Expert Answer
Present age of father = x2 years.
Present age of sun = x years
 
if father lives upto age 18x years means, number of years from present time = (18x -x2 ) years
 
age of son after (18x - x2) years = x+18x-x2 = 19x - x2 = x2 .................(1)
eqn. (1) is rewritten as, 19x -2x2 = 0   or 19 - 2x = 0    or   x = 9.5 years
 
Hence at present, son is 9.5 years old and father is 90.25 years old.
 
Though this question is solved as per the given information, the numbers are not reasonable.
we are getting fraction in present age of sun. Even if we accept the fraction,  fathers age is worked out as 90.25 years.
Father is expected to live upto 171 years.
 
Suppose this same question is changed as given below :
 
A man is x2 years old and his son is x years old now. If the man lives upto  the age of 11x  years his son is then x2 years old.
Find the present age of father and son
 
we will solve this modified question as earlier
 
Present age of father = x2 years.
Present age of sun = x years
 
 
if father lives upto age 11x years means, number of years from present time = (11x -x2 ) years
 
age of son after (11x - x2) years = x+11x-x2 = 12x - x2 = x2 .................(2)
eqn. (2) is rewritten as, 12x -2x2 = 0   or 12 - 2x = 0    or   x = 6 years
 
Hence at present, son is 6 years old and father is 36 years old.
 
when father's age is 11×6  = 66 years means, 30 years after the presnt time.
At that time son's age is 6+30 = 36 years.
 
Everything looks reasonable.
Answered by Thiyagarajan K | 28 Nov, 2018, 04:56: AM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
ICSE 10 - Maths
cot A - 1/ 2 - sec² = cot A / 1 + tan A
Asked by bhagvantingre | 24 Apr, 2024, 03:05: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
solve xdy-ydx=0
Asked by shaikafridi860 | 21 Apr, 2024, 11:22: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
if a is an acute angle and sec a = 17/8, find all other trigonometric rarios of angle a ( using trigonometric indentities).
Asked by aritramalakar4 | 13 Apr, 2024, 08:33: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
3√2x×x-5x-√2
question image
Asked by ashwanikaler9 | 11 Apr, 2024, 01:50: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
prove that
question image
Asked by botlarajshekhar | 22 Mar, 2024, 09:37: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
Mr. Gupta invested Rs. 33000 in buying Rs.100 shares of a company at 10% premium. The dividend declared by the company is 12% . Find: (a) the number of shares purchased by him. (b) his annual dividend
Asked by sagarmishra | 15 Mar, 2024, 03:22: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
 (a+b)²
Asked by dadoosumeksha | 13 Mar, 2024, 09:26: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
sheethal has a recurring deposit account in a bank and deposit rupees 300 and at rate of interest of 7℅ and recieved rupees 7725 on maturity, find the time which would the account will be held
Asked by jesnamariaroy2626 | 10 Mar, 2024, 11:28: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
if abc are in Continued proportion then prove that 3a2-4ab+5b2/3b2-4bc+5c2=a/c
Asked by vrj.parmar369 | 07 Mar, 2024, 11:27: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
sole
question image
Asked by ronaldlhouvum | 22 Feb, 2024, 02:42: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Get Latest Study Material for Academic year 24-25 Click here
×