Solution:

The man is 84 years old.
The son is 49 years old.
The grandson is 7 years old.

Solution:

757
+ 757
+ 45
======
1559

Solution:

It can be achieved as it is shown in the figure.

Solution:

They used the planks in the manner that is shown in the figure.

Solution:

Both of them were able to cross the river because they were standing on the opposite sides of the river.

Solution:

24

For Explanation : check picture solution.

Solution:

If you build a house on the South Pole, all of its walls will face towards North.

Solution:

3 3/4 hours

Explanation:
Suppose that the amount of petrol in each of the cars in the beginning was M.
Now, suppose that they drove for X hours.

In that case, the amount of petrol used by one car in X hours will be = M*X /4
The amount of petrol used by the other car will be = M*X/5

Therefore, the petrol left in one car = M - M*X / 4
Petrol left in the other car = M - M*X / 5

Now, according to the question,
M - M*X / 5 = 4 (M - M*X / 4)
=> X = 15 / 4 = 3 3/4 hours.

Therefore Murphy and Cooper drove for 3 3/4 hours.

Solution:

HEAVEN

Explanation:
ENEMY = 4 + 3 + 4 + 4 + 3 = 18
LINK = 2 + 1 + 3 + 3 = 9
HELL = 3 + 4 + 2 + 2 = 11
TAXI = 2 + 3 + 2 + 1 = 8
HEAVEN = 3 + 4 + 3 + 2 + 4 + 3 = 19

Using the same trick,
TAXI + HELL = 8 + 11 = 19 = HEAVEN.

Therefore, the required answer is HEAVEN.

Solution:

Rajesh will love villages but he will hate towns.

This is because he only likes things that contain double letters in their spelling.
The words balloons, swimming and weeds have double letters. Even villages has double letters and thus he will love villages.

Solution:

32 Degrees Fahrenheit at which Water Freezes.

Solution:

18

Solution:

doughnut

Solution:

There are 99 strawberry toffees in that jar.

We know for sure that there is at least one orange toffee in that jar. Now the question tells us that on picking two random toffees, one must be strawberry. This can only be possible if all the other 99 toffees are strawberry flavored.

Solution:

Word from the first row: AUGUST
Word from the second row: SCRIPT

Word from the circled letters: STRAPS or SPRATS.

Solution:

252

Explanation:
A unique pattern has been made into use in this series.
All numbers are (n^3 + n^2) where n is 1, 2, 3 and so on.

In first number, n = 1
1^3 + 1^2 = 1 + 1 = 2

In second number, n = 2
2^3 + 2^2 = 8 + 4 = 12

In third number, n = 3
3^3 + 3^2 = 27 + 9 = 36

In fourth number, n = 4
4^3 + 4^2 = 64 + 16 = 80

In fifth number, n = 5
5^3 + 5^2 = 125 + 25 = 150

Similarly for the sixth number, n = 6
6^3 + 6^2 = 216 + 36 = 252.

Solution:

All

Explanation:
The phrase 'all but five died' means that all except five died. This means that only five are left alive.

Solution:

18

Explanation:
More minutes implies more tea.
More women implies more tea.

The time become twice (3 minutes / 1.5 minutes).
women become six times (9 / 1.5).

Number of tea = 2 * 6 * Original(1.5)
= 18

Solution:

There are 99 strawberry toffees in that jar.

We know for sure that there is at least one orange toffee in that jar. Now the question tells us that on picking two random toffees, one must be strawberry. This can only be possible if all the other 99 toffees are strawberry flavored.

Solution:

The torque needed to hold up the longer piece is responsible for the fact that the shorter piece will weigh more. This is the reason why a heavier kid sits closer in on a see-saw against a lighter kid.