if 20th term and 30th term of Arthematic progression are 121 and 181 respectively find the 40th term of Arthematic progression​

Question

if 20th term and 30th term of Arthematic progression are 121 and 181 respectively find the 40th term of Arthematic progression​

in progress 0
Kaylee 2 months 2021-07-27T15:41:39+00:00 2 Answers 0 views 0

Answers ( )

    0
    2021-07-27T15:43:27+00:00

    Answer:

    241 Answer

    Step-by-step explanation:

    a_{20} = 121\\a_{30} = 181\\a_{40} = ?

    a_{20} = 121\\a + (20 - 1) * d = 121\\a + 19d = 121 ------equation 1\\a_{30} = 181\\a + (30-1) * d = 181\\a + 29d = 181 ----------equation 2\\Subtracting equation 2 from 1\\29d - 19d = 181 - 121\\10d = 60\\d = 6

    Putting value of d in equation 1

    a + 19(6) = 121

    a + 114 = 121

    a = 121-114

    a = 7

    Now, a40 = a + (40-1) X d

    = 7 + 39(6)

    = 7 + 234

    = 241 Answer

    0
    2021-07-27T15:43:35+00:00

    Answer:

    \huge\mathbb\fcolorbox{purple}{lavenderblush}{✰Answer}

    ✬ 40th Term = 241 ✬

    Step-by-step explanation:

    Given:

    20th and 30th term of an AP is 121 and 181 respectively.

    To Find:

    What is the 40th term of AP ?

    Solution: As we know that an AP series is given by

    ★ a + (n – 1)d ★

    • a = first term
    • n = number of terms
    • d = common difference

    A/q

    20th term is 121.

    ➙ a + (20 – 1)d = 121

    ➙ a + 19d = 121

    ➙ a = 121 – 19dㅤㅤㅤㅤㅤeqⁿ i

    Now ,

    30th term is 181

    ➙ a + (30 – 1)d = 181

    ➙ a + 29d = 181

    ➙ 121 – 19d + 29d = 181 ㅤㅤㅤfrom eqⁿ i

    ➙ 10d = 181 – 121

    ➙ d = 60/10 = 6

    So the common difference of AP is 6. Now putting the value of d in eqⁿ 1.

    ➮ a = 121 – 19 × 6

    ➮ a = 121 – 114

    ➮ a = 7

    So the first term of AP is 7.

    ∴ 40th term will be

    ⟹ a + (40 – 1)d

    ⟹ 7 + 39 × 6

    ⟹ 7 + 234

    ⟹ 241

    Hence, the 40th term of AP will be 241.

Leave an answer

Browse

9:3-3+1x3-4:2 = ? ( )