Question

in a class 40% students read maths,25% biology and 15%both maths and biology. 1 student is selected at random, probability,that he reads biology if he read maths​

Answer 1

students reading maths => 40 % = 40/100 = 2/5

students reading biology => 25 % = 25/100 = 1/4

students reading both => 15% = 15/100 = 3/20

hope it helps !!

Answer 2

TOTAL PERCENTAGE - 40 + 25 +15 = 80%

HENCE PROBABLITY THAT A STUDENT READS MATHS ASWELL AS BIO IS -

                               

                               15/80 = 3/16