Solution:

Six item that does not belong to this era are :
1. Plane
2. Table lamp.
3. Scooter.
4. Sunglasses.
5. Earphones
6. Mobile phone.

Solution:

3 and 7

Explanation:
Painters 3 and 7 are the only painters that match all nine circled areas.

Solution:

7

Explanation:
Put batteries into 3 groups: two groups of 3 and one group of 2.
It guarantees at least one of the group has got two working battery
Group of 3 requires 3 attempts to verify if 2 batteries of the group are working (B1+B2, B2+B3, and B1+B3) while the group of 2 requires one attempt (B1+B2)
Total attempts = 3 + 3 + 1 = 7

Solution:

The answer is shown in the below picture

Solution:

25

Explanation:
== Equation1 ==
RedFlower + RedFlower + RedFlower = 60
=> RedFlower = 20

== Equation2==
RedFlower + 5BluePetals + 5BluePetals = 30
=> 20 + 10BluePetals = 30
=> 10BluePetals = 10
=> 1BluePetals = 1

== Equation3 ==
5bluePetals + 2yellowFlower = 3
=> 5 + 2yellowFlower = 3
=> 2yellowFlower = 2
=> 1yellowFlower = 1

== Required ==
YellowFlower + RedFlower + 4BluePetals = ?
=> 1 + 20 + 4 = 25 ... The Answer

Solution:

12111

Explanation:
11000 + 1100 + 11 => 12111

Solution:

Point

ViewPoint, BoilingPoint, CheckPoint, and PinPoint are the common word used.

Solution:

This is a Perception riddle and hence there is no right or wrong attached to this answer.

It can be considered as a sound
> It makes the sounds of branches snapping and the almighty thump when the trunk hits the hard ground. The sound is sound and doesn't rely on people to interpret it.
> Yes. And isn't that a rather arrogant question, as what about all the animals that presumably hear it?

It cannot be considered as a sound because
> Does it depend on what you mean by 'sound'? The airwaves would still vibrate but without an ear/listening device to receive them, there would be no sound.
> The sound is something within human experience. Outside of this, it's just air (or whatever another medium) vibrating. If someone is there to hear it, it makes a sound, if not, it causes rapid movement of particles.

Solution:

49.

Please watch the video for an explanation.

Solution:

30.

For Explanation, watch video