4.A company selects an employee at his 25th age and offers salary as Rs.40000 per
annum for first 2 years. Afterwards, every year he gets increment of Rs.4000 for
next 15 years and his salary become constant till his retirement. If Rs.80,000 is
his average salary (throughout his career) then at what age he retires?

• For 1st 2 yrs salary=40,000
  After 2 years he get increment of 4000 every year for 15 years
  So 15th year salary =44000+14*4000=100000
  Now by using arithmetic progression
  S15=n/2(a+l)=15/2(44000+100000)=1080000
  Now avg salary=80000
  80000+10,80000+10,0000x/17+x=80000
  By solving
  x=10
  now 27+15+10=52
  so 52 is the age
  
  
• 9 years agoHelpfull: Yes(26) No(11)
• Employee's salary for first two years = Rs.40,000 (per annum)
  
  So, the total salary for first two years = Rs.80,000 ...(1)
  
  Given that, his salary increased by Rs.4000(per annum) for next 15 years.
  
  So, salary for next 15 years are 44,000, 48,000, 52,000,...
  Total salary for next 15 years is 44,000 + 48,000 + 52,000,...
  
  Note that, above sequence is an A.P with first term a = 44000, common difference = d = 4000, total number of terms = n = 15.
  We know that, sum of first n terms in A.P = (n/2)[2a+(n-1)d] and nth term = a+(n-1)d
  Therefore, 15th term = 44,000+(15-1)4000 = 1,00,000 ...(2)
  And the sum of 15 terms = 44,000 + 48,000 + 52,000,+... + 1,00,000
  = (15/2)[2x44000 + 14x4000]
  = (15/2)(144000) = 10,80,000 ...(3)
  
  From (1) and (3), the total salary of first 17 years = Rs.80,000 + Rs.10,80,000 = Rs. 11,60,000 ...(4)
  
  Form (2), we have, The salary of 17th year = Rs.1,00,000
  
  That is, till his retirement, his salary = Rs.1,00,000 (per annum) ...(5)
  
  Let the employee works for X more years.
  Then, the total salary for this X years = Rs.1,00,000 x X
  
  And his experience = 17 + X years ...(5)
  
  Given that, the average salary for 17+X years = Rs.80,000
  
  That is, Rs.80,000 = [Rs. 11,60,000 + RS.1,00,000 x X]/(17+X)
  (17+X)80,000 = [11,60,000 + 1,00,000 x X]
  (17+X)8 = [116 + 10X]
  [136-116] = 10X - 8X
  20 = 2X
  X = 10
  
  Therefore, from eqn 5, Employee's experience = 17+10 = 27 years.
  
  Since, he hired at his 25th age,his retirement age will be = 25+17 = 42.
  
  Hence, the answer is 42.
• 9 years agoHelpfull: Yes(21) No(12)
• Employee's salary for first two years = Rs.40,000 (per annum)
  
  So, the total salary for first two years = Rs.80,000 ...(1)
  
  Given that, his salary increased by Rs.4000(per annum) for next 15 years.
  
  So, salary for next 15 years are 44,000, 48,000, 52,000,...
  Total salary for next 15 years is 44,000 + 48,000 + 52,000,...
  
  Note that, above sequence is an A.P with first term a = 44000, common difference = d = 4000, total number of terms = n = 15.
  We know that, sum of first n terms in A.P = (n/2)[2a+(n-1)d] and nth term = a+(n-1)d
  Therefore, 15th term = 44,000+(15-1)4000 = 1,00,000 ...(2)
  And the sum of 15 terms = 44,000 + 48,000 + 52,000,+... + 1,00,000
  = (15/2)[2x44000 + 14x4000]
  = (15/2)(144000) = 10,80,000 ...(3)
  
  From (1) and (3), the total salary of first 17 years = Rs.80,000 + Rs.10,80,000 = Rs. 11,60,000 ...(4)
  
  Form (2), we have, The salary of 17th year = Rs.1,00,000
  
  That is, till his retirement, his salary = Rs.1,00,000 (per annum) ...(5)
  
  Let the employee works for X more years.
  Then, the total salary for this X years = Rs.1,00,000 x X
  
  And his experience = 17 + X years ...(5)
  
  Given that, the average salary for 17+X years = Rs.80,000
  
  That is, Rs.80,000 = [Rs. 11,60,000 + RS.1,00,000 x X]/(17+X)
  (17+X)80,000 = [11,60,000 + 1,00,000 x X]
  (17+X)8 = [116 + 10X]
  [136-116] = 10X - 8X
  20 = 2X
  X = 10
  
  Therefore, from eqn 5, Employee's experience = 17+10 = 27 years.
  
  Since, he hired at his 25th age,his retirement age will be = 25+27 = 52.
  
  Hence, the answer is 52.
• 8 years agoHelpfull: Yes(11) No(1)
• ans is 25th=40,000
  till 27th=40,000
  28th=44,000
  .
  .
  37th=80,000
  so ans is 37 years
  
• 9 years agoHelpfull: Yes(5) No(8)
• Employee's salary for first two years = Rs.40,000 (per annum)
  
  So, the total salary for first two years = Rs.80,000 ...(1)
  
  Given that, his salary increased by Rs.4000(per annum) for next 15 years.
  
  So, salary for next 15 years are 44,000, 48,000, 52,000,...
  Total salary for next 15 years is 44,000 + 48,000 + 52,000,...
  
  Note that, above sequence is an A.P with first term a = 44000, common difference = d = 4000, total number of terms = n = 15.
  We know that, sum of first n terms in A.P = (n/2)[2a+(n-1)d] and nth term = a+(n-1)d
  Therefore, 15th term = 44,000+(15-1)4000 = 1,00,000 ...(2)
  And the sum of 15 terms = 44,000 + 48,000 + 52,000,+... + 1,00,000
  = (15/2)[2x44000 + 14x4000]
  = (15/2)(144000) = 10,80,000 ...(3)
  
  From (1) and (3), the total salary of first 17 years = Rs.80,000 + Rs.10,80,000 = Rs. 11,60,000 ...(4)
  
  Form (2), we have, The salary of 17th year = Rs.1,00,000
  
  That is, till his retirement, his salary = Rs.1,00,000 (per annum) ...(5)
  
  Let the employee works for X more years.
  Then, the total salary for this X years = Rs.1,00,000 x X
  
  And his experience = 17 + X years ...(5)
  
  Given that, the average salary for 17+X years = Rs.80,000
  
  That is, Rs.80,000 = [Rs. 11,60,000 + RS.1,00,000 x X]/(17+X)
  (17+X)80,000 = [11,60,000 + 1,00,000 x X]
  (17+X)8 = [116 + 10X]
  [136-116] = 10X - 8X
  20 = 2X
  X = 10
  
  Therefore, from eqn 5, Employee's experience = 17+10 = 27 years.
  
  Since, he hired at his 25th age,his retirement age will be = 25+27 = 52.
  
  Hence, the answer is 52.
• 8 years agoHelpfull: Yes(4) No(0)
• Which i S the crct ans pls tel
  
• 9 years agoHelpfull: Yes(1) No(3)
• its clearly 52 ans
• 9 years agoHelpfull: Yes(1) No(4)
• (x-25)*80000=40000*2+40000*15+4000*15+(x-25-15-2)*(40000+4000*15)
  x=73
• 9 years agoHelpfull: Yes(1) No(7)
• At age of 25,,,salary=40,000
  At age of 26,,,,salary=40,000
  now for nxt 15 year,,,age will b=26+15+1=42 (1--bcoz he is not retired in 15th year,,job goes on)
• 9 years agoHelpfull: Yes(1) No(1)
• answer is : 37 year
• 9 years agoHelpfull: Yes(0) No(4)
• 5 subjects can be arranged in 6 periods in 6P5 ways.
  Remaining 1 period can be arranged in 5P1 ways.
  Two subjects are alike in each of the arrangement. So we need to divide by 2! to avoid overcounting.
  Total number of arrangements = (6P5 x 5P1)/2! = 1800
  
  Alternatively this can be derived using the following approach.
  5 subjects can be selected in 5C5 ways.
  Remaining 1 subject can be selected in 5C1 ways.
  These 6 subjects can be arranged themselves in 6! ways.
  Since two subjects are same, we need to divide by 2!
  Total number of arrangements = (5C5 × 5C1 × 6!)/2! = 1800
• 8 years agoHelpfull: Yes(0) No(2)
• 40 000 + 40 000 + (40 000 + 4000) + (40 000 + 2 * 4000) + (40 000 + 3*4000) + ...... + (40 000 + 15*4000) =
  80 000 + 15*40 000 + 4000*(15 * (15-1)/2) ) = 1 100 000 = cumulatif salary for 17 years
  
  15 * 4000 + 40 000 = 100 000 = constant salary from 18 year
  
  average = (1 100 000 + x*100 000) / (17+x) = 80 000 => x = 13
  
  age = 25 + 2 + 15 + 13 = 55
• 8 years agoHelpfull: Yes(0) No(3)