Which of the following pairs is not correctly matched?

In a certain code language, 'GOLF' is coded as '6428' and 'OPEN' is coded as '7653'. What is the code for 'O' in the given code language?

Read the given statement and conclusions carefully. Decide which of the given conclusions is/are definitely true from the statement.

Select the figure from among the given options that can replace the question mark (?) in the following series.

Select the correct combination of mathematical signs to sequentially replace the * signs and balance the given equation.

21 * 3 * 36 * 2 * 23 = 68

Select the option that is related to figure C in the same way as figure B is related to figure A.

Three of the following four options are alike in a certain way and thus form a group. Which is the one that does NOT belong to that group?

How many triangles are there in the given figure?

What should come in place of ? in the given series?

64  61   55   46  34  ?