Accedmychevron_right11thchevron_rightmathchevron_rightSequences And Serieschevron_rightExercise 6.2

Questions

  1. Question 1

    Find the common difference and write the next two terms of each arithmetic sequence.

  2. Question 2

    Write the first three terms of each arithmetic sequence, with given information.

  3. Question 3

    Find an+1a_{n+1} and a2na_{2n} if an=4+3na_n = 4 + 3n.

  4. Question 5

    The 18th and 30th terms of an arithmetic sequence are 367 and 499 respectively. How many terms of this sequence are less than 1000?

  5. Question 6

    Is 301 a term of the A.P. 5,11,17,5, 11, 17, \ldots?

  6. Question 7

    If 2x,x+8,3x+12x, x+8, 3x+1 are in A.P., then find the value of xx.

  7. Question 8

    Which term of the A.P. 3,8,13,3, 8, 13, \ldots is 123?

  8. Question 9

    Which term of the A.P. 30,29.5,29,30, 29.5, 29, \ldots is the first negative term?

  9. Question 10

    The 7th and 21st terms of an A.P. are 37 and 107 respectively. Find the A.P. and its 100th term.

  10. Question 11

    If 1ac,1bc,1ba\dfrac{1}{a-c}, \dfrac{1}{b-c}, \dfrac{1}{b-a} are in A.P., then show that abac=acba\dfrac{a-b}{a-c}=\dfrac{a-c}{b-a}.

  11. Question 12

    How many numbers of three digits are divisible by 7?

  12. Question 13

    Find the 8th term from the end of the A.P. 8,11,14,,1858, 11, 14, \ldots, 185.

  13. Question 14

    Find the nthn^{th} term of the progression (37)10,(107)10,(177)10,\left(\dfrac{3}{7}\right)^{10}, \left(\dfrac{10}{7}\right)^{10}, \left(\dfrac{17}{7}\right)^{10}, \ldots. Is the progression an A.P.?

  14. Question 15

    If the arithmetic progressions 3,10,17,3, 10, 17, \ldots and 63,65,67,63, 65, 67, \ldots are such that their nthn^{th} terms are equal, then find the value of nn.

  15. Question 16

    If the pthp^{th} term of an A.P. is qq and the qthq^{th} term is pp, prove that its nthn^{th} term is (p+qn)(p+q-n).

  16. Question 17

    If 1a,1b,1c\dfrac{1}{a}, \dfrac{1}{b}, \dfrac{1}{c} are in A.P., show that b=2aca+cb=\dfrac{2ac}{a+c}.

  17. Question 18

    If 1a,1b,1c\dfrac{1}{a}, \dfrac{1}{b}, \dfrac{1}{c} are in A.P., show that the common difference is ac2ac\dfrac{a-c}{2ac}.

  18. Question 19

    If aka_k and ama_m denotes two different terms of an A.P., show that its nthn^{th} term is ak+(nk)(akamkm)a_k+(n-k)\left(\dfrac{a_k-a_m}{k-m}\right).

  19. Question 20

    If a1,a2,a3,,ana_1, a_2, a_3, \ldots, a_n are positive and in A.P., prove that 1a1+a2+1a2+a3++1an1+an=n1a1+an\dfrac{1}{\sqrt{a_1}+\sqrt{a_2}}+\dfrac{1}{\sqrt{a_2}+\sqrt{a_3}}+\cdots+\dfrac{1}{\sqrt{a_{n-1}}+\sqrt{a_n}}=\dfrac{n-1}{\sqrt{a_1}+\sqrt{a_n}}.

  20. Question 21

    If the roots of the equation (bc)x2+(ca)x+(ab)=0(b-c)x^2+(c-a)x+(a-b)=0 are equal, show that a,b,ca, b, c are in A.P.

  21. Question 22

    If the sides of a right-angled triangle are in A.P., find the ratio of its sides.

  22. Question 23

    If the nthn^{th} term of a progression is a linear expression in nn, then prove that this progression is an A.P.