Question

in a class of 48,boys&girls are in the ratio 3:1 find the number of girls to be added to make the ratio 2:1​

Answer 1

Step-by-step explanation:

Of the 45 members of the students council the ratio of boys to girls is 2:1. Add 2 and 1 to get 3, which means 2/3*45 = 30 are boys and 15 girls.

Add x more girls to get (15 + x) girls. Now the total number of council members is (45+x). The new ratio will be

(15 + x)/(45+x) = 2/5 or

5*(15 + x) =2*(45+x), or

75 + 5x = 90 + 2x, or

5x - 2x = 90 -75, or

3x = 15, or

x = 5.

Check: New council has 45+5 = 50 members. Girls in the new council are 15 + 5 or 20. Boys are 30, girls are 20, hence ratio is 3:2.

Adding 5 more girls is the answer

Answer 2

Answer:

48:x::3:1

48/x÷3/1

48/x×1/3

x=16 girls

48:x::2:1

48/x÷2/1

48/x×1/2

x=24 girls