Question

In the following question, a matrix of certain characters is given.These characters follow a certain trend, row-wise or column wise.Find out this trend and choose the missing character accordingly.

13	12	5
17	15	8
25	24	?
29	21	20

• A. $7$
• B. $9$
• C. $11$
• D. $15$

Answer 1

Answer: (A)

$7$

Clearly, (3rd column)${}^2$ + (2nd column)${}^2$ = (1st column)${}^2$

In the first row, $5^2+{12}^2={13}^2$.

In the second row, $8^2+{15}^2={17}^2$.

Let the missing number in the third row be y.

Then $y^2+{24}^2={25}^2$ or $y^2+576=625$ or $y^2=49$ or $y=7.$