Question

1.explain 7x11x13+13 is a composite number but 2x6x3x5+1 is not composite number
2.if HCF(24,x)=6 and LCM(24,x)=144 find the value of x

Answer 1

Answer1:7*11*13+13=1014 which is divisible by 1,2,13etc. So it is a composite number.

2*3*6*5+1=181 which is divisible only by 1 and 181. Thus it is a prime number.

Answer2:Lcm*hcf=product of numbers

6*144=24x

X=6*144/24

X=36