Mr Lim put some red pens and blue pens into a box . The ratio of the number of red pens to the number of blue pens was 3: 4 .He pet another 20 red pens into the box and the ratio of the number of red pens to the number of blue pens became 2:1 (a) How many red pens were there in the end? (b) How many blue pens were there?

Respuesta :

Answer:

a) There were 32 red pens and b) 16 blue pens.

Step-by-step explanation:

3:4

for 3:4 to be 2:1 we should add 5 in order for it to be 8:4 (2:1)

20 divided by 5 is equal to 4

8:4

8 times 4 is equal to 32

4 times 4 is equal to 16

The number of red pens that were there, in the end, is 32 pens while the number of blue pens that were there, in the end, is 16 pens

If the ratio of the number of red pens to the number of blue pens was 3: 4,

If  20 red pens are added into the box and the ratio of the number of red pens to the number of blue pens became 2:1, this means that the  5 is added to  the original ratio to have:

(5+3): 4 = 8:4

The number of red pens in the end  = [tex]8 \times \frac{20}{5}=8\times 4 = 32[/tex]

The number of red pens in the end  = [tex]4 \times \frac{20}{5}=4\times 4 = 16[/tex]

Hence the number of red pens that were there, in the end, is 32 pens while the number of blue pens that were there, in the end, is 16 pens

Learn more here:

https://brainly.com/question/3796978