Which one of the following is not a prime number?

Since 8 men in 24 days can reap 80 hectares.
? 1 men in 24 days can reap 80 / 8 hectares.
? 1 men in 1 days can reap 80 / 8 x 24 hectares.
? 36 men in 1 days can reap 80 x 36 / 8 x 24 hectares.
? 36 men in 30 days can reap 80 x 36 x 30 / 8 x 24 hectares.
? 36 men in 30 days can reap 10 x 36 x 30 / 24 hectares.
? 36 men in 30 days can reap 10 x 3 x 30 / 2 hectares.
? 36 men in 30 days can reap 10 x 3 x 15 hectares.
? 36 men in 30 days can reap 450 hectares.

As we know that Quarter Kg = 250 Gram
According to question,
250 Gram of potato costs 60 paise.
? 1 Gram of potato costs 60 / 250 paise.
? 200 Gram of potato costs 60 x 200 / 250 paise.
? 200 Gram of potato costs 60 x 20 / 25 paise.
? 200 Gram of potato costs 60 x 4 / 5 paise.
? 200 Gram of potato costs 12 x 4 paise.
? 200 Gram of potato costs 48 paise.

According to given question,
Since an industrial loom weaves 0.128 meters of cloth in 1 seconds.
? an industrial loom weaves 1 meters of cloth in 1 / 0.128 seconds.
? an industrial loom weaves 25 meters of cloth in 1 x 25 / 0.128 seconds.
? an industrial loom weaves 25 meters of cloth in 25 / 0.128 seconds.
? an industrial loom weaves 25 meters of cloth in 195 seconds.

Let the marked price = ? N
The discount equivalent to successive discounts 20 % and 10 % = { r₁ + r₂ - (r₁ r₂)/100 } %
Where, r₁ = 20 and r₂ = 10
Then, 30 - 2 = 28 %
According to the question,
{(100 - 28)N}/100 - {(100 - 30)N}/100 = 72
? (72N - 70N)/100 = 72
? N = (72 x 100)/2 = ? 3600

Given that, one root of the equation
x² - bx + c = 0 is square of other root of this equation i.e., roots (?, ?²).
? Sum of roots = ? + ?² = -(-b)/1
? ? (? + 1) = b .......(i)
and product of roots= ?. ?² = c/1
? ?³ = c ? = c^1/3 ....(ii)
From Eqs. (i) and (ii).
c^1/3 (c^1/3 + 1) = b ....(iii)
On cubing both sides, we get
c(c^1/3 + 1)³ = b³
? c {c + 1 + 3c^1/3 (c^1/3 + 1)} = b³
? c {c + 1 = 3b} = b³ [from Eq. (iii)]
? b³ = 3bc + c² + c

∴  x = 2.

2x + 3y = 29 ...(i)
and y = x + 3 ...(ii)
Putting the value of y from Eq. (ii) to Eq. (i), we get
2x + 3y = 29
2x + 3(x + 3) = 29
2x + 3x + 9 = 29
? 5x = 20
? x = 4

Let the wages of 1 man, 1 woman and 1 boy are ? P, ? Q and ? R, respectively. According to the question,
3P + 2Q + 4R = 26 ....(i)
3P = 4Q ....(ii)
and 2Q = 3R ....(iii)

From Eqs. (i) and (ii), we get
4Q + 2Q + 4R = 26
? 6Q + 4R = 26.........................(iv)

From Eqs. (iii) and (iv), we get
9R + 4R = 26
? 13R = 26
? R = 2
From Eqs. (ii) and (iii), we get
Q = 3 and P = 4

? Wages of 4 men, 3 women and 2 boys
= (4 x 4) + (3 x 3) + (2 x 2)
= 16 + 9 + 4 = ? 29

[?3 + x + ?3 - x] / [?3 + x - ?3 - x] = 2

Let ?3 + x = a and ?3 - x = b
Then, (a + b) / (a - b) = 2/1
? a + b = 2a - 2b
? a = 3b

? ?3 + x = 3?3 - x

On squaring bothv sides, we get
(?3 + x)² = (3?3 - x)²
? 3 + x = 9(3 - x)
? 3 + x = 27 - 9x
? 10x = 24
? x = 12/5

Let us assume the numbers are a and b.
According to question,
sum of two numbers = 25
a + b = 25......................(1)
difference of two numbers = 13
a - b = 13........................(2)
add the Equation (1) and (2)
a + b+ a - b = 25 + 13
? 2a = 38
? a = 19
Put the value of a in equation in (1)
19 + b = 25
? b = 25 - 19
? b = 6
Product of the numbers = a x b
put the value of a and b,
? Product of the numbers = 19 x 6
? Product of the numbers = 114