So for this question, it is better to draw a table:
----------------White-----------Blue-----------Total
----------|-------------------|---------------|
Colonial
----------|-------------------|---------------|
Ranch
----------|-------------------|---------------|
Total
Now as we are given that 40 % are colonial, hence 60 % will be a ranch
----------------White-----------Blue-----------Total
----------|-------------------|---------------|
Colonial ----------------------------------------40
----------|-------------------|---------------|
Ranch-------------------------------------------60
----------|-------------------|---------------|
Total--------------------------------------------100
Of the 40 % colonial houses, 25% are white so 25% of 40% = 10%, and 40 % of all houses are white.So ranch and white will be 30%
----------------White-----------Blue------------Total
----------|-------------------|---------------|
Colonial-------10--------------------------------40
----------|-------------------|---------------|
Ranch---------30----------------X---------------60
----------|-------------------|---------------|
Total----------40-----------------60--------------100
The question asks what percent of homes are ranch and blue.So we need the value of X
As we can see 30+X =60, Hence X =30 %.
Answer :
BIn percent questions, we can also use 100 as the total number of houses.
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Satish Sharma
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