Correct Answer - Option 4 : Rs 21,000

**Given:**

Average sales from 2014 to 2017 = Rs. 106000

Average sales from 2015 to 2018 = Rs. 138000

Sales in 2018 = Rs. 149000

**Formula used:**

Average = sum of observations/total number of observations

**Calculation:**

Total sales in 2014, 15, 16, 17 = 4 × 106000 = Rs. 424000

Total sales in 2015, 16, 17, 18 = 4 × 138000 = Rs. 552000

Total sales in 2015, 16, 17 = 552000 - 149000 = Rs. 403000

Sales in 2014 = 424000 - 403000 = Rs. 21000

**∴ The sales were Rs 21000**