Q. What is the value of X in the sequence 20, 10, 10, 15, 30, 75, X?
a. 105
b. 120
c. 150
d. 225
Correct Answer: d. 225
Question from UPSC Prelims 2022 CSAT Paper
Explanation :
20,10,10,15,30,75
1 20 x 0.5 = 10
2 10 x 1.0 = 10
3 10 x 1.5 = 15
4 15 x 2.0 = 30
5 30 x 2.5 = 75
6 75 x 3.0 = 225
We can see that to obtain X, we need to multiply the previous term (75) by 3. Therefore, the value of X is:
X = 75 x 3 = 225
Therefore, the correct answer is (d) 225.
