Question

Which number will best complete the relationship given below?
7:64 :: 8:?
A)82
C)80
B)79
D)81​

Answer 1

Question :--- Which number will best complete the relationship given below?

7:64 :: 8:?

A)82

C)80

B)79

D)81

Answer :---

Lets First see the relationship between 7 and 64 .

→ if we add 1 in 7 and than Square the number we get, our result .

So,

→ (7+1)² = 8² = 64 .

In analogy, we have to do same in Second part ,

So,

→ (8+1)² = 9² = 81 (D) (Ans).

Hence, 81 will be suitable answer here...

Answer 2

★ Question :-

Which number will best complete the relationship given below?

7:64 :: 8:?

A)82

B) 80

C) 79

D) 81

$\rule{400}{4}$

★ Solution :-

1st Method

Firstly, we will see the numbers on L.H

S

Numbers are 7:64

We will do square of 7 and then add 15. We will get the another number

We get,

→(7)² + 15

→ 49 + 15

→ 64

$\rule{200}{2}$

Same as R.H.S

(8)² = 64

Now, we will add 15 to the square of 8.

(8)² + 15

64 + 15

79

∴ Correct Option is C) 79

$\rule{400}{4}$

2nd Method

As, Given in L.H.S

7: 64

Or

7:(8)²

Similarly, do on L.H.S

We get,

8:(9)²

8:81

∴ Correct Option is D) 81.