Find the digit that makes _2,530 divisible by 9. a.6 b.5 c.7 d.8

Option d.

Step-by-step explanation:

The given number is

_2,530

We need to find the missing digit so that the given number is divisible by 9.

Rule of divisibility of 9 : If the sum of all digits of a number is divisible by 9, then that number must be divisible by 9.

The sum of given digits is

If the missing number is 6, then sum of all digits is

16 is not divisible by 9, so 6 can not be the missing number.

If the missing number is 5, then sum of all digits is

15 is not divisible by 9, so 5 can not be the missing number.

If the missing number is 7, then sum of all digits is

17 is not divisible by 9, so 7 can not be the missing number.

If the missing number is 8, then sum of all digits is

18 is divisible by 9, so the missing number is 8.

Therefore, the correct option is d.

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13