Question

531:64::365:169::786:400::983:?

Answer 1

The given pattern is 531:64::365:169::786:400::983:?

When we observe this pattern,

64 is related to 531,169 is related to 365, 400 is related to 786 similarly  number in ? related to 983.

we get 64 =[(5 + 3 +1)- 1]^2

169 = [(3+6+5) -1]^2=13^2

400 = [(7+8 + 6)- 1]^2 = 20^2

So the next number is from 983

therefore 983 gives [(9+8+3)-1]^2=19^2=361

number 361 replace the question mark.

so the pattern is

531:64::365:169::786:400::983: 361

Answer 2

The given pattern is 531:64::365:169::786:400::983:x

When we observe this pattern,

64 is related to 531,

169 is related to 365,

400 is related to 786

similarly  number in x related to 983.

we get 64 =[(5 + 3 +1)- 1]^2

169 = [(3+6+5) -1]^2=13^2

400 = [(7+8 + 6)- 1]^2 = 20^2

and

the next number is from 983

therefore 983 gives

[(9+8+3)-1]^2=19^2=361

number 361 replace x

hence the pattern is

531:64::365:169::786:400::983: 361