AGE

AGE

In Exam these types of questions asked very few question 

WORDS THAT TRICK YOU:

PAST(-)                          Ago,Back,Before,Earlier,Was,Were,Last Year
PRESENT(Now)             Is,Now,Are
FUTURE(+)                        After,Hence,Next year,Later,Tomorrow,Will be,Shall be

We all ways Use X for the Different Persons For Preset Year Ages----------(1)

There is no use to use any formulas We directly get into the Question Solving

1) The sum of father and son is 45 years.five years ago,the product of their ages was four times the father's age at that time.The present ages of father and son,respectively are:    

PRESENT:

Sum=45==>Father(f)+Son(S)

F+S=45

F=45-S

Take Son as X---------By (1)

S=X

F=45-X

PAST:

Five years ago(Past) so -5

F=(45-X-5)

S=X-5

Product of their age==>(X-5)*(45-X-5)

Four times the fathers age==>4(45-X-5) 

NOW:

(X-5)*(45-X-5)=4(45-X-5) 

(X-5)=4

X=9

F=45-X=36

S=X=9

2) The ratio of the present ages of Sunitha and Vinita is 4:5 respectively.Six years hence the ratio of their ages will be 14:17 respectively.what will be the ratio of their ages 12 years hence?

 NOW:

Ratio S:V=4:5

FUTURE:

Six year hence(Future)

S+6 : V+6==>

4X+6 : 5X+6=14:17

Cross muliply

17(4X+6)=14(5X+6)

68X+102=70X+84

2X=18

X=9

FUTURE:

12 Years hence: 

4X+12 : 5X+12  

NOW:

(4*9)+12 : (5*9)+12

36+12 : 45+12

48 : 57

16:19

3) Ratio of sumita and shalini's age is 4:5 respectively,Ratio of Shalini and ritu's age is 15:16 respectively.If sumita is three-fourth Ritu's age,what is sumita's age?

Ratio SU:SH=4:5

SH:RI=15:16

SU:SH:RI=?

4 : 5

   15 : 16

(4*3):(5*3)

        (15*1):(16*1)

12:15:16

SU = 3/4 RI

SU=?

Here We don't Know the Sum of their Age We only know is The Part Hold by Each person So it can't determined the answer.

4) When the average age of a couple and their son was 42 years,the son married and got a child after one year.When the child was 5 years old,the average age of the family become 36 years.What was the age of the daughter-in-law at the time of marriage?

Average C+S==>M+W+C==> members

C+S=42

Sum=42*3=126

Son Married Got Child After 1 year

Son's Child was 5 year old

The Average C1+C2+S1+S2==>M1+W1+M2(Son become men)+W2+S2==>5 members

C1+C2+S2=?

Sum=(Before the M2 married sum is 126) + (After 1 year+child 5 year total 6 years=>6 * before M2 married 3 members=(6*3)) 18 + (we dont know the W2 Age so Take it X) X + (Child age) 5=(Total members=5)*(Average=36)

Sum  : (126+(3*6)+X+5=5*36

Sum :149+X=180

X=31

This X is afer 1+ child 5 year

So 31-6=25

the daughter-in-law age at the time of marriage=25

     

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RATIO AND PROPORTION

RATIO AND PROPORTION

The ratio is Denoted as X:Y

X:Y=X/Y

Eg:

Value=40
That in the Ratio 5:3
then the 5 part of 40=?
               3 part of 40=?
40/(5+3)=40/8=5
One part value=5
Then 5 part=5*5=25
         3 part=5*3=15
25+15=40

QUESTION AND ANSWER

If the position of the digits of a two digit number are interchanged,the number newly formed is smaller then the original number by 45.Also the ratio between new number and the original number is 3:8 respectively.what is the original number?

The two digit number=XY

Interchanged number=YX

YX is smaller then original by 45==>XY=YX+45-----(1)

YX:XY=3:8-------(2)

XY-YX=45------By (1)

3~8=YX~XY

5=45

one part=8 so

YX= 3 part=3*8=27----------By(2)

XY= Interchage of digits=72

Original number=72

(OR)

10X + Y=10Y+X+45

9X-9Y=45

X-Y=5--------(1)

(10Y+X)/(10X+Y)=(3/8)

30X+3Y=80Y+8X

22X-77Y=0--------(2)

Solve (1) and (2)

55Y=110

Y=2

X=7

Original number=72

The digits of a two digit number are in the ratio of 2:3 and the number obtained by interchanging the digits is bigger then the original number by 27 what is the original number ?

XY=>X:Y=>2:3

YX-XY=27

Here individual digit ratio is given so try to trace from options 

1)63

2)48

3)96

4)69

we know they are in 2:3 ratio so 96 eliminated

yx-xy=27

36-63= not possible

84-48=(2+30+4)=36 Wrong

96-69=(1+26)=27 Right Answer

(OR)

Eg:

------------

56=50+6

(10*X)+6

X=5

------------

We knew the two digit number is always 10 th unit+some X

So 10X-Y---->Original number

X:Y=2:3 

(10Y+X)-(10X+Y)=27----->(1)

9Y-9X=27

Y-X=3

Y=X+3--------->Put in(1)

X/(X+3)=(2/3)

X=6

Y=9

Original number=69

Ages of A and B in the ratio 2:3 Respectively,

Six year hence the ratio of their ages will become 8:11 Respectively,

What is B's Present age ?

A/B=2/3

Six years Hence(After)

A/B=8:11

Now2X/3X

After 6 Years (2X+6)/(3X+6)=8/11

cross multiply them

11(2X+6)  = 8(3X+6)

22X+66  = 24X+48

22X-24X=48-66

2X=18

X=9

Now=>18:27

A=18

B=27

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