Jee Main 2024 01 02 2024 Shift 1 - Question4
Question 4
If $3,7,11, \ldots, 403=A P _1$
$2,5,8, \ldots ., 401=A P _2$
Find sum of common term of $A P _1$ and $A P _2$
(1) 3366
(2) 6699
(3) 9999
(4) 6666
Show Answer
Answer: (2)
Solution:
$3,7,11,15,19,23,27, \ldots 403=A P _1$
$2,5,8,11,14,17,20,23, \ldots 401=A P _2$
so common terms A.P.
$11,23,35, \ldots, 395$
$\Rightarrow 395=11+(n-1) 12$
$\Rightarrow 395-11=12(n-1)$
$\frac{384}{12}=n-1$
$32=n-1$
$n=33$
Sum $=\frac{33}{2}[2 \times 11+(32) 12]$
$=\frac{33}{2}[22+384]$
$=6699$
BETA
