(x+1),3x and (4x+2) are first three terms of an AP. Find its 5th term.
24
For a set of numbers to be in AP, the difference between any two consecutive terms should be constant.
If a1,a2,a3 are in AP, then
a2−a1=a3−a2 = d
where 'd' is the common difference.
Given, (x+1),3x,(4x+2) are in AP
∴3x–(x+1)=(4x+2)–3x
⇒x=3
∴ a1 = (x+1) = 3+1 = 4
a2 = 3x = 9
d = a2−a1 = 9 - 4 = 5
The formula to find the nth term of an arithmetic progression is tn=a1+(n−1)d
where,
'a1' is the first term,
'd' is the common difference,
'n' is the no. of terms,
'tn' is the nth term.
Substituting the values, we get
t5=4+4(5)=24