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D06 Math
Question 7
2021 June(D06) Math Question 7
Sequences and Patterns
- Arithmetic Sequences
Choice C
$$a_1=6 \\$$ $$d=3 \\$$ $$a_n=a_1+(n-1)d \\$$ $$=> a_{21}=a_1+(21-1)\times3=66$$
Choice C$$a_1=6 \\$$ $$d=3 \\$$ $$a_n=a_1+(n-1)d \\$$ $$=> a_{21}=a_1+(21-1)\times3=66$$