JEE 2023 — Mathematics PYQ
JEE | Mathematics | 2023Let A=[aij],aij∈Z∩[0,4],1≤i,j≤2. The number of matrices A such that the sum of all entries is a prime number p∈(2,13) is
Choose the correct answer:
- A.
204
(Correct Answer) - B.
214
- C.
224
- D.
304
204
Explanation
1. Jab Sum S=3 ho
Yahan formula (r−1n+r−1) lagega:
N3=(4−13+4−1)=(36)=20
2. Jab Sum S=5 ho
Yahan ek entry 5 nahi ho sakti, isliye (35+3) mein se wo cases minus karenge jahan koi ek entry ≥5 ho:
N5=(38)−4(30+3)=56−4(1)=52
3. Jab Sum S=7 ho
Yahan bhi wahi logic (Total - Cases where any xi≥5):
N7=(37+3)−4(32+3)=(310)−4(35)=120−4(10)=80
4. Jab Sum S=11 ho
Isme "Inclusion-Exclusion" use hoga:
N11=(311+3)−4(36+3)+6(31+3)
N11=364−4(84)+6(4)=364−336+24=52
Final Total Calculation
Total=N3+N5+N7+N11
Total=20+52+80+52=204
Answer: 204
Explanation
1. Jab Sum S=3 ho
Yahan formula (r−1n+r−1) lagega:
N3=(4−13+4−1)=(36)=20
2. Jab Sum S=5 ho
Yahan ek entry 5 nahi ho sakti, isliye (35+3) mein se wo cases minus karenge jahan koi ek entry ≥5 ho:
N5=(38)−4(30+3)=56−4(1)=52
3. Jab Sum S=7 ho
Yahan bhi wahi logic (Total - Cases where any xi≥5):
N7=(37+3)−4(32+3)=(310)−4(35)=120−4(10)=80
4. Jab Sum S=11 ho
Isme "Inclusion-Exclusion" use hoga:
N11=(311+3)−4(36+3)+6(31+3)
N11=364−4(84)+6(4)=364−336+24=52
Final Total Calculation
Total=N3+N5+N7+N11
Total=20+52+80+52=204
Answer: 204

