Directions: Study the table below carefully and answer the given question.

The table displays the total number of laptops sold by five different stores (P, Q, R, S, and T), which sell two brands of laptops (Dell and HP), along with the ratio of Dell laptops sold to HP laptops sold by each store.

Stores	Total number of Laptops (Dell and HP)	Ratio of Dell Laptops : HP Laptops
P	400	$2:3$
Q	550	$6:5$
R	700	$3:4$
S	600	$8:7$
T	250	$11:14$

If 40% of the Dell laptops and 60% of the HP laptops sold by Store Q are defective, find the total number of non-defective laptops (both Dell and HP) sold by Store Q.

The correct answer is 280.

Step 1: Calculate the total number of Dell and HP laptops sold by Store Q.
From the given table, for Store Q:
Total number of laptops sold (Dell and HP) = 550
Ratio of Dell laptops to HP laptops = 6 : 5

Total ratio parts =

$6+5=11$

Number of Dell laptops sold by Store Q:

$\text{Dell laptops}=\left(\frac{6}{11}\right)\times 550=300$

Number of HP laptops sold by Store Q:

$\text{HP laptops}=\left(\frac{5}{11}\right)\times 550=250$

Step 2: Calculate the number of non-defective laptops for Store Q.
Percentage of defective Dell laptops = 40%
Percentage of non-defective Dell laptops = 100% - 40% = 60%

Number of non-defective Dell laptops:

$60\text{\% of}300=\frac{60}{100}\times 300=180$

Percentage of defective HP laptops = 60%
Percentage of non-defective HP laptops = 100% - 60% = 40%

Number of non-defective HP laptops:

$40\text{\% of}250=\frac{40}{100}\times 250=100$

Step 3: Find the total number of non-defective laptops (both Dell and HP) sold by Store Q.

$\text{Total non-defective laptops}=180+100=280$

Thus, the total number of non-defective laptops sold by Store Q is 280.