Mathematics
Finding the $n$th term of an AP
Practice questions
The (n)th-term formula of the AP (23,31,39,\ldots) is (a_n=8n+15). What is the (36)th term?If (a_{n+1}-a_n=11) and (a_7=58), what is (a_{17})?In an AP (a_1+a_2=41) and (d=7). What is (a_{10})?If in an AP (a_7+a_{19}=156), what is the value of (a_{13})?In the AP (128,119,110,\ldots), which is the last term greater than (30)?If in an AP (a_7=31) and (a_{19}=103), what is the value of (a_{34})?In an AP, (a_4+a_{16}=86) and (a_{10}=43). Find (a_{25}) when the common difference is (5).If (a_n=3n+p) and (a_{12}=50), what is (a_{27})?In an AP, (a_{2m}=58), (a_m=31), and (d=3). What is the value of (m)?Which is the first term of the AP (41,35,29,\ldots) that is less than (-50)?If the (5)th term of an AP is (x+7) and the (12)th term is (x+42), what is the (20)th term in terms of (x)?In an AP, (a_{11}=4a_3) and (a_3=18). What is (a_{15})?In an AP, (a_8=27) and (a_{18}=77). Which term will be (152)?If (a_n=kn+5) and (a_{15}-a_6=63), what is (a_{20})?What is the first term greater than (200) in the AP (2,9,16,\ldots)?In an AP, (a_p=17), (a_{p+8}=65), and (p=6). What is (a_{30})?If in an AP (a_3+a_9=72), what is the value of (a_6)?In an AP, (a_2+a_5+a_8=111). Find the value of (a_5).If (a_1=12) and it is not (a_n=3a_{n-1}+2) but an AP with (a_n=12+(n-1)d), and (a_9=68), what is (a_{22})?At the end of consecutive hours, the water level in a tank is recorded as 84.5 cm, 81.75 cm, 79.0 cm, ... A student says that the water level at the end of the 16th hour will be \(84.5-16\times2.75=40.5\) cm. Which is the correct analysis of the student's error?