Answer: Option B. -> 10.75%
Number of employees in IT department
= 800 × $$\frac{20}{100}$$
= 160
Number of females
= 160 - 74
= 86
∴ Required percentage
= $$\frac{86}{800}$$ × 100
= 10.75%

Answer: Option D. -> 55 : 9
Total employees in Marketing department = 192
Males = 165
Females = 192 - 165 = 27
∴ Required ratio
= 165 : 27
= 55 : 9

Answer: Option A. -> 7 : 10
Number of employees in HR department
= $$\frac{5}{100}$$ × 800
= 40
Numbers of females
= 40 - 12
= 28
∴ Ration = 28 : 40 → 7 : 10

Answer: Option B. -> 86%
Number of employees in marketing department
= $$\frac{24}{100}$$ × 800
= 192
∴ Required percentage
= $$\frac{165}{192}$$ × 100
= 85.93%
≈ 86%

Answer: Option C. -> 40%
Number of Dell laptops sold by store T
$$\eqalign{
& = 2400\times\frac{21}{100} \cr
& = 504 \cr} $$
Number of Laptops sold by store P
$$\eqalign{
& = 2400\times \frac{15}{100} \cr
& = 360 \cr} $$
Required Percentage
$$\eqalign{
& = \frac{504-360}{360}\times100 \cr
& = 40\% \cr} $$

Answer: Option D. -> 38%
Percent of Dell Laptops sold by store Q = 25%
Total number of Dell Laptops bold by store Q
$$\eqalign{
& = 2400\times\frac{25}{100} \cr
& = 600 \cr} $$
Percent of Laptops Dell and Lenovo sold by store R = 35%
Number of Laptops Dell and Lenovo sold by store R
$$\eqalign{
& = 4500\times\frac{35}{100} \cr
& = 1575 \cr
& \therefore \text{Required Percentage} \cr
& = \frac{600}{1575}\times100 \cr
& = 38.095 \cr
& \approx 38\% \cr} $$

Answer: Option B. -> 99
Percent of Laptops Dell and Lenovo sold by store Q = 23%
Number of Laptops Dell and Lenovo sold by store Q
$$\eqalign{
& = 4500\times\frac{23}{100} \cr
& = 45\times23 \cr
& = 1035 \cr} $$
Percent of Laptops Dell and Lenovo sold by R and S together
  = 35% + 11%
  = 46%
Now, total number of Laptops Lenovo and Dell sold by R and S together
$$\eqalign{
& = 4500\times\frac{46}{100} \cr
& = 2070 \cr} $$
Percent of Dell Laptops sold by R and S together
  = 30% + 9%
  = 39%
Number of Dell Laptops sold by R and S together
$$\eqalign{
& = 2400\times\frac{39}{100} \cr
& = 936 \cr} $$
Number of Lenovo Laptops = 2070 - 936 = 1134
Required difference
  = 1134 - 1035
  = 99

Answer: Option B. -> 432
Percent of Dell Laptops sold by P, R and S together
= 15% + 30% + 9%
= 54%
Total Dell Laptops sold by P, R and S together
$$\eqalign{
& = 2400\times\frac{54}{100} \cr
& = 1296 \cr
& \therefore \text{ Average} \cr
& = \frac{1296}{3} \cr
& = 432 \cr} $$

Answer: Option D. -> 32.4°
Dell laptops sold by store S = 9%
Central angle corresponding to number of Dell Laptops sold by store S
$$\eqalign{
& = \frac{9}{100}\times360 \cr
& = 32.4° \cr} $$

Answer: Option D. -> Rs. 649500
Number of mobile phones sold by B during October
$$\eqalign{
& = 45000\times\frac{8}{100}\times\frac{5}{12} \cr
& = 1500 \cr
& \therefore \text{Required profit} \cr
& = \text{Rs. }\left(1500\times433\right) \cr
& = \text{Rs. 649500} \cr} $$