Question

In tina's new class there are 55 students. This is 1.25 times the number of students in her old class. How many students were there in her old class​

Answer 1

Step-by-step explanation:

ANSWER

Given , N=55,n(M)=23,n(P)=24,n(C)=19,n(M∩P)=12,n(P∩C)=7,n(M∩C)=9,n(M∩P∩C)=4

Now, number of students studying only Mathematics

n(M∩P

′

∩C

′

)=n(M)−n(M∩P)−n(M∩C)+n(M∩P∩C) (by Venn diagram)

=23−9−12+4=6

Now, number of students studying only Physics

n(P∩M

′

∩C

′

)=n(P)−n(P∩M)−n(P∩C)+n(P∩M∩C) (by Venn diagram)

=24−12−7+4=9

Now, number of students studying only Chemistry

n(C∩M

′

∩P

′

)=n(C)−n(C∩M)−n(C∩P)+n(M∩P∩C) (by Venn diagram)

=19−9−7+4=7

So, the number of people who study exactly one of the three subjects =6+9+7=22

Mark answer as brain list

follow me

Answer 2

Answer:

44

Step-by-step explanation:

Let the number of students in her old class be x.

ATQ,

x * 1.25 = 55

=> x = 55/1.25

=> x = 44.

.°. the number of students in her old class was 44.

Hope it helps you.