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Question
Fill up the boxes and find out the number of terms in the A.P.
1,3,5,....,149 .
Here a = 1 , d =b`[ ], t_n = 149`
tn = a + (n-1) d
∴ 149 =`[ ] ∴149 = 2n - [ ]`
∴ n =`[ ]`
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Solution
In the A.P. 1,3,5,....,149
a = 1 , d = 2 , tn = 149
tn = a + (n-1)d
149 = 1+ (n-1) × 2
149 = 1 + 2n -2
149 = 2n - 1
∴ 2n = 150
∴ n = 75
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