Information and Communication Technology - Number System

Option : A
Explanation : A number is divisible by 3 if the sum 'of all its digits is divisible by 3.From the given options, only 97632 is divisible by3 because 9 + 7 + 6 + 3,+ 2 = 27, which is divisible by 3.

Option : B
Explanation : We know that a number Which is made by writing a 2-digit number 3ctimes, then the number is divisible by 7 and 13. Now, we are to check the divisibility of 11 only. Sum of digits at odd places in 787878 == 7 + 7 + 7 = 21 Sum of digits at even places in 787878 = 8 + 8 + 8.= 24 Difference =24-21= 3, which is not divisible by 11. Therefore, 787878 is not divisible by 11.

Option : B
Explanation : First,we will check the divisibility by 9. Sum of the digits of the given number 7 + 7 + 4+ 9+5+ 8+ $\fn_jvn \small _{N1}$ +9+6+ $\fn_jvn \small _{N2}$ = 55+ $\fn_jvn \small _{N1}$ + $\fn_jvn \small _{N2}$ By taking option one-by-on,e, we take 1. 55 + 7 + 8 = 70 is not divisible by 9. 2. 55 + 0 + 8 = 63 which is divisible by 9. Now, we will check the divisible by 8 For it, take last three digits 96 $\fn_jvn \small _{N2}$ =968 which is divisible by 8. Hence, the number 7749580968 is divisible by both. 8 and 9.

Option : D
Explanation : A.number is divisible by 4 if the number made by last ,two digits is divisible by 4. In the given number, last two digits i.e. 24 is divisible by 4. So,'x' can take any of the values.