In 2017 the sales of each brand increased by the same percentage as it did in the year 2016. What will be the approximate average sales (in units) of mobiles per brand in year 2017?

Increase in sales of brand 1 in 2016 = $$\frac{7.5-5.5}{5.5}\times100=36.36\%$$

=> Sales of brand 1 in 2017 = $$7.5+(7.5\times\frac{36.36}{100})=10.2$$

Increase in sales of brand 2 in 2016 = $$\frac{6-5}{5}\times100=20\%$$

=> Sales of brand 2 in 2017 = $$6+(6\times\frac{20}{100})=7.2$$

Increase in sales of brand 3 in 2016 = $$\frac{7.5-6.5}{6.5}\times100=15.38\%$$

=> Sales of brand 3 in 2017 = $$7.5+(7.5\times\frac{15.38}{100})=8.625$$

Increase in sales of brand 4 in 2016 = $$\frac{9.5-8.5}{8.5}\times100=11.76\%$$

=> Sales of brand 4 in 2017 = $$9.5+(9.5\times\frac{11.76}{100})=10.545$$

$$\therefore$$ Average sales (in '000 units) of mobiles per brand in year 2017 = $$\frac{10.2+7.2+8.625+10.545}{4}$$

= $$\frac{36.57}{4}\times1000 \approx 9175$$

=> Ans - (A)