How many triangles are there in the given figure?

The second number in the given number pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) are followed in all the number pairs, EXCEPT one. Find that odd number pair.

Which of the following numbers will replace the question mark (?) in the given series?
 1724, 1716, 1689, 1625, 1500, ?

Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
 A B Z _ P A B _ K P A B X K _ A B _ K P

Three statements are given, followed by three conclusions numbered I, II and III. Assuming the statements to be true, even if they seem to be at variance with commonly known facts, decide which of the conclusions logically follow(s) from the statements.

Statements:
 All pencils are erasers.
 All sharpeners are erasers.
 All compasses are sharpeners.

Conclusions:
 I. All compasses are erasers.
 II. Some compasses are pencils.
 III. Some erasers are compass.

Study the given pattern carefully and select the number that can replace the question mark (?) in it.
 First row- 2, 57, 7
 Second row- 6, 225, 3
 Third row- 5, ?, 2
 (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding /deleting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is NOT allowed)

Select the correct combination of mathematical signs to sequentially replace the * signs and to balance the given equation.
 25 *5 * 10 * 2 * 4 * 10

The following sentence has been split into four segments. Identify the segment that contains a grammatical error.

When we got / to the train station, / the Rajdhani Express / had already been leaving.