Solution:

==== 65 ==== 35 ====
== 34 === 31 === 4 ==
= 10 == 24 == 7 == -3 =

Solution:

288/61 hours (4 hours, 43 minutes and 17 seconds approx)

Explanation:
In 1 hour, the ratio of swimming pool filled by pipes:
1st pipe: 1/48
2nd pipe: 1/72
3rd pipe: 1/96
4th pipe: 1/6

All togther
1/48 + 1/72 + 1/96 + 1/6
=> (6+4+3+48) / 288 = 61/288.
=> 288/61 hours,

which is 4 hours 43 minutes and about 17 seconds.

Solution:

developers=2, testers=5 and content-writters=13

Explanation:
Let the number of developers, testers, and content-writers are denoted by d, t, and c respectively.

From the given information we can write the following 2 equations;
d + t + c = 20 . . . . . . (1)
3d + 1.5t + 0.5c = 20 . . . . . (2)

Multiplying equation (2) by 2 we get;
6d + 3t + c = 40 . . . . . (2)

equation3 - equation 1
5d + 2t = 20

The unique solution with whole numbers is d = 2 & t = 5

Therefore from equation(1) we can find;
c = 13

developers=2, testers=5 and content-writters=13.

Solution:

7 Trips

Explanation:
Send 2+5+9 = 16
Bring back 9
Send 3+4+9 = 16
Bring back 9
Send 1+7+8 = 16
Bring back 1
Send 1+6+9 = 16

Solution:

3 lbs.

Explanation:
Based on information provided, we can deduce that
3/4 lbs = 1/4 of soap weight
=> soap weight = 4 x 3/4 = 3 lbs

Solution:

I Over Ate

Explanation:
Check the mathematical solution on the image below.
Also, 8 in 2018 resembles a fat person.

Solution:

2 Ways

Explanation:
1 + 2 + 34 + 56 + 7 = 100.
1 + 23 + 4 + 5 + 67 = 100.

Solution:

100

Solution:

0488

Explanation
A) Its a 4 digit number. --- 0488

B) Its first digit is of no use --- 0 at the start is of no use.

C) Its third and fourth digit is the mirror image of each other. --- 8 is the only digit which is a mirror image of itself.

D) The second digit is half the third. --- 4 is half of the digit 8.

Solution:

8m

Explanation:
From green bar, it's clear that
the height of vertical bar = 2/3 of uninterrupted shadow length

Therefore shadow of 6m of red bar indicates the height of 4m.
The remaining red bar casts a direct 1:1 vertical projection on the wall.

Therefore total length = 4m + 4m = 8m.