Practice30 Create account

Explain why $7 \times 11 \times$ 13 + 13 is a composite number.
Find which prime divides it for sure.

Class 10Fundamental Theorem of ArithmeticNumber Systems

A13
B7
C11
DIt is prime

Step-by-Step Solution

7 \times 11 \times 13 + 13 = 13 \times (7 \times 11 + 1) = 13 \times 78

, which has factors other than 1 and itself, so it is composite; 13 clearly divides it.

Answer: A) 13

Master this chapter in 30 minutes a day.

Don't just memorise the answer — build a daily practice habit.

Practice 5 Similar Questions Free →

All Fundamental Theorem of Arithmetic practice questions

More Class 10 Fundamental Theorem of Arithmetic practice

A shopkeeper in Pune has two ropes of length 84 m and 120 m. He wants to cut both into…Two tankers contain 850 litres and 680 litres of diesel. Find the maximum capacity of a…Check whether 6^n can end with the digit 0 for any natural number n. Choose the correct…In a school assembly in Chennai, students of Class A (number 24) and Class B (number 36)…The HCF of 65 and 117 can be expressed as 65m - 117. The value of m is: