Old workers and new workers

[vishal.pathak]

A factory has 500 workers, 15% of whom are women. If 50 additional workers are to be hired and all present workers remain. How many of additional workers must be women in order to raise the percent of women employees to 20%.

A. 3
B. 10
C. 25
D. 30
E. 35

OA E

I have a doubt in this question

I used the allegation of mixtures
The proportion needed of each ingredient is equal to the distance between the OTHER two percentages.

Let the % of women in new workers be x

so ration of old to new workers can be written as

(x-20)/(20-15) = 500/50 or x = 30%

30% of 50 = 15. Please help me find my mistake

Regards,
Vishal

[vishal.pathak]

A factory has 500 workers, 15% of whom are women. If 50 additional workers are to be hired and all present workers remain. How many of additional workers must be women in order to raise the percent of women employees to 20%.

A. 3
B. 10
C. 25
D. 30
E. 35

OA E

I have a doubt in this question

I used the allegation of mixtures
The proportion needed of each ingredient is equal to the distance between the OTHER two percentages.

Let the % of women in new workers be x

so ration of old to new workers can be written as

(x-20)/(20-15) = 500/50 or x = 30%

30% of 50 = 15. Please help me find my mistake

Regards,
Vishal

Got my mistake - Thanks

Apologies for creating a new thread

[tpr-becky]

If 15% of the 500 workers are women that means that there are 75 women in the first group.

if you add 50 workers then you have a total of 550 workers and you want 20% of them to be women. 20% of 550 is 110 so you need 110 women. if you have 75 women originally then you need to add 35 women to get to the 20%.