The mean of 9 observations is 16. One more observation is included and the new mean becomes 17. The 10th observation is :

[A]9

[B]16

[C]26

[D]30

**26**

Mean of ten observations – Mean if nine observations = Tenth observation

= 10 17 – 16 9

= 170 – 144 = 26

Hence option [C] is correct answer.