Please proofread your question.
How can 64 out of 60 students pass biology?
in a class of 60 student,64 passed biology and 42 passed chemistry.every student passed at least one of the two subjects.How many student passed in both subject?
2 answers
42 - both = chem alone
64 - both = bio alone
chem alone + bio alone + both = 60
both = b
chem alone = c
bio alone = d
so
42 - b = c
64 - b = d
-------------subtract
-22 = c-d
c+d+b = 60
c+ b = 42
-----------------subtract
d = 18
then b = 64 - d = 46
NOTE - impossible BECAUSE you have a typo
In a class of 60, 64 did NOT pass biology :)
However this is how to do it when you get it right.
64 - both = bio alone
chem alone + bio alone + both = 60
both = b
chem alone = c
bio alone = d
so
42 - b = c
64 - b = d
-------------subtract
-22 = c-d
c+d+b = 60
c+ b = 42
-----------------subtract
d = 18
then b = 64 - d = 46
NOTE - impossible BECAUSE you have a typo
In a class of 60, 64 did NOT pass biology :)
However this is how to do it when you get it right.
2 answers