JEE Main 2020 Mathematics question

The mean and the standard deviation (s.d.) of 10 observations are 20 and 2 respectively. Each of these 10 observations is multiplied by p and then reduced by q, where and . If the new mean and new s.d. become half of their original values, then q is equal to -

• (A)– 10
• (B)– 5
• (C)– 20Correct
• (D)10