Question

after 4 years sum of a,b ages are 80 years present their ratio is 7.5 then a present age is​

Answer 1

It seems minor mistake in the question ;

Correct Question :

After 4 years sum of a,b ages are 80 years present their ratio is 7 : 5 then A's present age is?

Answer:

• The A's present age = 42 years.

Given :

• After 4 years sum of a,b ages are 80 years.

• Their present ratio is 7 : 5.

To find :

• A's present age =?

Step-by-step explanation:

Let, the a and b ages be 7x and 5x.

After 4 years a's age = 7x + 4

After 4 years b's age = 5x + 4

According to the question :

➟ (7x + 4) + (5x + 4) = 80

➟ 7x + 4 + 5x + 4 = 80

➟ 7x + 5x + 4 + 4 = 80

➟ 12x + 8 = 80

➟ 12x = 80 - 8

➟ 12x = 72

➟ x = 72/12

➟ x = 6

Hence,

The A's present age = 7x ⟹ 7 × 6 = 42 years.

Verification :

Put the value of x in (7x + 4) + (5x + 4) = 80.

∴ ( 7 x 6 + 4) + ( 5 x 6 + 4) = 80

42 + 4 + 30 + 4 = 80

80 = 80

L. H. S = R. H. S

Hence, it is verified.

Answer 2

❥${\red{\underline{\underline{\huge{\mathtt{Question:-}}}}}}$

After 4 years sum of a and b ages are 80 years . The ratio of their present age is 7:5. Find the present age of a.

❥${\red{\underline{\underline{\huge{\mathtt{Solution:-}}}}}}$

•${\green{\bold{Present\:age\: ratio\:of\:a\:and\:b\: =7:5}}}$

Consider,

•${\red{\bold{Present\:age\:of \:a\: = \:7x}}}$

•${\blue{\bold{Present\:age\:of \:b\: = \:5x}}}$

After 4 years, age of a = ${\green{\bold{(7x+4)\: years}}}$

After 4 years, age of b= ${\orange{\bold{(5x+4)\: years}}}$

The sum of their ages = 80 years.

${\purple{\bold{According\:to\:the\: question,}}}$

${\bold{(7x+4)+(5x+4)\:=\:80}}$

${\bold{→7x+4+5x+4\:=\:80}}$

${\bold{→12x+8\:=\:80}}$

${\bold{→12x\:=\:80-8}}$

${\bold{→12x\:=\:72}}$

${\bold{→x\:=\:\frac{72}{12}}}$

${\bold{→x\:=\:6}}$

So, present age of a = ${\orange{\bold{7×6\: years}}}$

${\green{\bold{\:\:\:\:\:\:\:\:\:\:\:\:= 42 \: years}}}$

❥${\red{\underline{\underline{\huge{\mathtt{Answer:-}}}}}}$

Present age of a is 42 years.