The passenger train takes 2 hours less for a journey of 300 km if it's speed is increased by 5 kilometre per hour from its normal speed. The normal speed is:

Let the normal speed be "S" kilometre/hour

New speed=(S+5) km/ hr

(300/s)-2=300/(s+5)

On solving this equation we get:

S=25 km/hr.

.
The average of 5 quantities is 6. The average of 3 of them is 8. What is the average of the remaining two numbers?

The average of 5 quantities is 6.

Therefore, the sum of the 5 quantities is 5 *6 = 30.

The average of the 3 of these 5 quantities is 8.

Therefore, the sum of these 3 quantities = 3*8 = 24

The sum of the remaining two quantities = 30 - 24 = 6.

Average of these two quantities = 6 / 2 = 3.

.
In following questions, one term in number series is incorrect.

Find out the incorrect number 10, 14, 28, 32, 64, 68, 132

Find out the incorrect number 10, 14, 28, 32, 64, 68, 132

Alternately, the numbers are increased by four and doubled to get the next number>

Thus, 10 + 4 = 14;

14 * 2 = 28;

28 + 4 = 32;

32 * 2 =64 and so on.

So, 132 is wrong and must be replaced by (68 * 2) i.e. 136..