Out of the 400 students in a final year in secondary school, 300 are offering biology and 190 are offering chemistry. I) how many student are offering both subject , if only 70 students are offering neither biology nor chemistry? I) how many students are offering at least one biology and chemistry?

I) how many student are offering both subject , if only 70 students are offering neither biology nor chemistry?

= 160 students

II) how many students are offering at least one biology and chemistry?

= 330 students

Step-by-step explanation:

I) how many student are offering both subject , if only 70 students are offering neither biology nor chemistry?

Total number of student n ( B ∪ C) = 400

Students offering biology n(B) = 300

Students offering chemistry n(C) = 190

Students not offering biology nor chemistry = 70

Students offering both biology and chemistry n ( B ∩ C) = ??

n ( B ∪ C) - Students neither offering biology nor chemistry = n(B ) + n ( C ) - n ( B ∩ C)

400 - 70 = 300 + 190 - n ( B ∩ C)

330 = 490 - n ( B ∩ C)

n ( B ∩ C) = 490 - 330

n ( B ∩ C) = 160

Therefore, students offering both Biology and Chemistry are 160 students.

II) how many students are offering at least one biology and chemistry?

n(B' ) + n ( C') + n ( B ∩ C)

n(B') = Students offering biology only

= n(B) - n ( B ∩ C)

= 300 - 160 = 140

n(C') = Students offering chemistry only

n(C) - n ( B ∩ C)

= 190 - 160

= 30

(300 - 160) + (190 - 160) + 160

140 + 30 + 160

= 330 students

its kinda hard to answer this when we dont have all the information that we need.