Question

the present ages of derek and saniya are in the ratio 3:4.Five years from now the ratio of their ages will be 4:5.Find their present ages?​

Answer 1

Answer:

Derek=15, Saniya=20

Step-by-step explanation:

let, Derek's current age be $3x$

and, Saniya's current age be $4x$

or, given that

$3x+5:4x+5= 4:5\\\\or, \frac{3x+5}{4x+5}=\frac{4}{5}\\or, 5(3x+5)=4(4x+5)\\or, 15x+25= 16x+20 \\or, 25-20= 16x-15x\\or, x=5$

thus, Derek's present age is $3x=3$×$5$ = $15$

similarly, Saniya's present age is $4x=4$×$5= 20$