Question

in an exam 400 students appeared if 2/3of the boys and all 130 girls passed in the exam then find how many boys failed in the exam​

Answer 1

let the total number of boys = x

2/3 of boys are passed, which means 2/3 of x are passed which gives 2/3x

and if 2/3x are passed then 1/3x are failed in exam

by the above we will get,

$\frac{1x}{3} + \frac{2x}{3} + 130 = 400$

solving this we will get

$\frac{3x}{3} + 130 = 400$

then

x + 130 = 400

x = 400 - 130

x = 270

Total no. of boys is 270

Boys failed in exams,

$\frac{x}{3} = \frac{270}{3} = 90$