Home › ICSE Class 10 › mathematics › Arithmetic Progression › If a_n = 3 n + 5, the first three terms are
If a_n = 3 n + 5, the first three terms are
A8, 11, 14
B5, 8, 11
C3, 6, 9
D8, 13, 18
Answer & Solution
Correct answer: A. 8, 11, 14
1. Plug n = 1: a_1 = 3 + 5 = 8.
2. n = 2: a_2 = 6 + 5 = 11.
3. n = 3: a_3 = 9 + 5 = 14.
4. So the AP starts 8, 11, 14.
_Source: Selina Concise Mathematics Class 10, Ch on Arithmetic Progression (Mistral OCR'd PDF), section on nth term formula_
Related questions
Rupees 720 was divided among A, B, C, D and E. The amounts received were in ascending ordeIf S_n = n^2 + 3 n, then first term and common difference areHow many three-digit numbers are divisible by 6?If sum of an AP is 100 and a = 5, l = 15, number of terms isSum of all natural numbers between 100 and 200 divisible by 7 isMiddle term of the AP 1, 5, 9, ..., 49 isSum of an AP with first term 7, last term 47 and 9 terms isIf 4th term is 11 and 9th term is 26, first term is