Question

the ratio between the mark obtained by two students A and B is 2:3.To appreciate their creative thinking the teacher has decided to give grace marks of 5 to each of them. if the ratio of their marks is now 5:7, find the mark obtained by each of them initially​

Answer 1

Step-by-step explanation:

Let the ratio of the initial marks obtained by A and B be 2x and 3x respectively.

According to the Question,

$\sf \dfrac{2x +5}{3x + 5} = \dfrac{5}{7}$

$\sf \implies 7(2x+5) = 5(3x+5)$

$\sf \implies 14x+35=15x +25$

$\sf \implies 35-25 = 15x -14x$

$\sf \implies 10 = x$

Marks obtained by A = 2x = 2(10) = 20

Marks obtained by B = 3x = 3(10) = 30.

Hope it helps!