Correct Answer - Option 4 : 3013
Calculation:
LCM of 18, 21 and 24 is 504
Let the number be 504k
According to the question
⇒ 504k – [(18 – 7) + (21 – 10) + (24 – 13)]/3
⇒ 504k – (33/3)
⇒ 504k – 11
Put the value of k so that it should be divisible by 23
Put k = 6
⇒ 504 × 6 – 11
⇒ 3024 – 11
⇒ 3013
∴ The number is 3013