In three more years, Mithun's grandfather will be six times as old as Mithun was last year. When Mithun's present age is added to his grandfather's present age, the total is 68. How old is each one now?
Answers
Present age of Mithun= m
Present age of grandfather = f
When Mithun's present age is added to his grandfather's present age, the total is 68
f+m=68
f=68-m...............(1)
In 3 years,
grand father present age = f+3
Mithun was last year = m-1
In 3 years, mithun's grandfather will be six times as old as Miguel was last year Miguel's grandfather will be six times as old as.
f+3=6(m-1)
f+3=6m-6
f=6m-6-3
f=6m-9...........(2)
Put the value of f from (1) to (2)
68-m=6m-9
-m-6m=-9-68
-7m=-77
Divide by -7 both sides
-7m/-7=-77/-7
m=11
Put the value of m in (1)
f=68-m
f=68-11
f=57
Present age of Mithun = m = 11
Present age of grandfather = f = 57
Check
Sum of their ages = 11+57 = 68
Last year Mithun was = 11-1 = 10
In three years Grandfather will be = 57+3 = 60 (which is 6 times of 10)
let mithuns grandpas age be x and mothuns age be y
x+3=6y
= x-6y=-3 (1)
x+y=68 (2)
substract 1 and 2
×-6y=-3
×+y=68
= -5y = -65
y= 13
x= 68- 13
= 55