# Math Ratios

posted by .

The ratio of the number of pupils in Class A to the number of pupils in Class B is 2:5. The ratio of the pupils in Class B to the number of pupils in Class C is 10:3.
a. Find the ratio of the number of pupils in Class A to the number of pupils in Class B to the number of pupils in Class C.
b. If there are 70 pupils in Class A and Class C altogether, how many pupils are there in Class B?
c. If Class B has 40 pupils, how many pupils are there in Class A and Class C altogether?

• Math Ratios -

A : B = 2 : 5 or 4 : 10 (looking at the next line)
B : C = 10 : 3

so A : B : C = 4 : 10 : 3

b)

A : C = 10 : 3
so 3A = 10C ---> A = 10C/3
also A+C = 70
12C/3 + C = 70
12C + 3C = 210
15C = 210
C = 14
B = 56

c) I assume we go back to the original definition, and the count is different from b)
A : B : C = 4:10:3
A:40:C = 4:10:3 = 16:40:12
Then A 16 , C=12
A+C = 28

## Similar Questions

1. ### Number sence

In mrs. Kyoto's class,7/10 of the pupils have pets.of those pupils,4/7 have cats.what fraction of the class has pet cats?
2. ### MATHS

Class A and Class B have the same number of pupils. The ratio of the number of boys in Class A to the number of boys in class B is 3:2. The ratio of the number of girls in Class A to the number in Class B is 3:5. Find the ratio of …
3. ### algebra

In a class there is 40 pupils.26 pupils plays volley ball and 20 pupils play foot ball and 17 pupils play both of game.how many pupils does not play game?
4. ### Maths

30% of the pupils in a class are boys.there are 21 girls.how many pupils are there in the class in all?
5. ### Maths

30% of the pupils in a class are boys.there are 21 girls.how many pupils are there in the class in all?
6. ### math

Roger buys six 1.5- litre bottles of fresh juice. he distributes 20 cl of juice to each of his pupils. calculate the number of pupils in his class if 600 ml is left.
7. ### maths

In a class 20 pupils like science, 13 pupils like history,8 pupils like both subjects and 9 pupilz do no not like either subject..use a Venn diagram to find how many pupils were in the class.....?
8. ### Math

In a class,12 pupils are in the band and 3/4 of the remaining pupils are in the modern dance club. If 1/5 of the class are in neither the band nor the club,how many pupils are there in the class?
9. ### maths

In a class 2/5 of the pupils wear sprctacles.(a)What fraction of the pupils do not wear spectacles?
10. ### maths

54% of the pupils in a class are girls. what % of pupils are boys?

More Similar Questions