Question

8) Three of the given four options are obtained by
multiplying two consecutive natural numbers. Which is
the odd one out?
A) 72
B) 42
C) 152
D) 110​

Answer 1

Answer:

Step-by-step explanation:

Let the two consecutive natural numbers be x and (x+1)

From the given condition, we have

x(x+1)=72

⇒x  

2

+x=72

⇒x  

2

+x−72=0

⇒x  

2

+9x−8x−72=0

⇒x(x+9)−8(x+9)=0

⇒(x−8)(x+9)=0

⇒x−8=0 or x+9=0

⇒x=8 or x=−9

∵−9 is not a natural number.  

So, x=8 and x+1=8+1=9.

Hence, the numbers are 8 and 9