X is a number between 10 and 25. The Possible values of x are
11 12 13 14 15 16 17 18 19 20 21 22 23 24
(one of these numbers) x (a unknown number) = 360
Did you notice that there are prime numbers in the middle.( 11,13….23)
None of the prime numbers divide 360 – 13,17,19, 23
Rule out the primes. Whats left………….
12 14 15 16 18 20 21 22 24
(one of these numbers) x (a new number) = 360
This means 360 is perfectly divisible by either of these two numbers.
Take one number at a time
360 /12 .. its divisible … keep it..
360/14 = 360/(7×2) is not an integer ….360 is not divisible by 7.. rule it out
360/16 = 360/(4×4) is not an integer… 360 is not divisible by 4 twice.. rule it out
360/21 = 360/(7×3) is not an integer….360 is not divisible by 7.. rule it out
360/22 = 360/(2×11) is not an integer…360 is not divisible by 11.. rule it out
Whats left.. 12 15 18 20 24
There are five such possibilities
Answer option: B