Answer: Option B Given: T4:T7::2:3 Let's find the common difference (d) of the given AP using the formula: d = (T7 - T4) / 3 = (3T4 - 2T4) / 3 = T4 / 3 Now, we can find T4 in terms of the first term (a) using the relation Tn = a + (n-1)d: T7 = a + 6d => 3T4 = a + 9d Substituting the value of d, we get: 3T4 = a + 3T4 / 3 => 9T4 = a + T4 => a = 8T4 Thus, we have a = 8T4 and d = T4 / 3 Using the same relation Tn = a + (n-1)d, we can find T3 and T11 in terms of T4: T3 = a + 2d = 8T4 + 2(T4/3) = (26/3)T4T11 = a + 10d = 8T4 + 10(T4/3) = (38/3)T4 Now, we can find T3:T11 as: T3:T11 = (26/3)T4 : (38/3)T4 = 26:38 = 13:19 Therefore, the correct answer is option B, i.e., T3:T11 = 5:13.If you think the solution is wrong then please provide your own solution below in the comments section .
Let a be the first term and d be the common difference.Now, t4t7 = 23⇒a+3da+6d = 23⇒3a+9d = 2a+12d⇒a = 3dNow,t3t11 = a+2da+10d = 3d+2d3d+10d = 5d13d = 513
sivapriyanka 2018-05-30 08:28:21
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FORMULA:
a+(n-1)d;
a+3d=2;a+6d=3;on solving we get,
a=1,d=1/3;
substitute it on the equation,
a+2d and a+10d
we get 5:13
2 Comments
FORMULA:
a+(n-1)d;
a+3d=2;a+6d=3;on solving we get,
a=1,d=1/3;
substitute it on the equation,
a+2d and a+10d
we get 5:13
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