Explanation

Using formula:

$b^2-4ac=0$

Here:

• $a = 2$
• $b=-k$
• $c = 5$

So:

(−k)^2−4(2)(5)=0
k^2−40=0
k^2=40

±2√(10)

$$Last\; updated\; question\; NS\; on\; 10\; MAY\; 2026$$

Explanation

Average of 8 persons = 12.5

So total weight:

$$8 times 12.5 = 100$$

One person of 18 kg is replaced by 10 kg:

New total:

$$100-18+10=92$$

New average:

$$92÷8=11.5$$

$$Last\; updated\; question\; NS\; on\; 10\; MAY\; 2026$$

Explanation

Ratio of boys : girls = 9 : 11

Total parts:

$$9+11=20$$

Total students = 80

Girls

$$frac{11}{20} times 80 = 44$$

$$Last\; updated\; question\; NS\; on\; 10\; MAY\; 2026$$

Explanation

Assume cost price = 100

Marked price = 25% above CP:

$$100+25=125$$

Discount = 10% on 125:

$$10\%\text{ of }125=12.5$$

Selling price:

$$125-12.5=112.5$$

Profit

$$112.5 - 100 = 12.5$$

$$Last\; updated\; question\; NS\; on\; 10\; MAY\; 2026$$

Explanation

Let original price = x

Step 1: Apply 25% discount

Discounted price =

$$x-25\%\text{ of }x=0.75x$$

Step 2: Apply tax (55% on discounted price)

Final price =

$$0.75x\times 1.55=1.1625x$$

Given final price = 1260

1.1625x=1260
x=1260​/1.1625=1083.87≈1084

Last updated question NS on 10 MAY 2026

Explanation

Let original number = 100

Step 1: Increase by 12%

$$100+12=112$$

Step 2: Decrease 112 by 12%

12% of 112=13.44
$$112-13.44=98.56$$

Step 3: Compare with original

Original = 100
Final = 98.56

Decrease =

$$100-98.56=1.44$$

Percentage change:

$$1.44\%$$

$$Last\; updated\; question\; NS\; on\; 10\; MAY\; 2026$$

Explanation

Average of 3 numbers = 26

So total sum:

$$3\times 26=78$$

Given:

• First number = 16
• Second number = 31

Sum of first two:

$$16+31=47$$

Third number:

$$78 - 47 = 31$$

$$Last\; updated\; question\; NS\; on\; 10\; MAY\; 2026$$

Explanation

Profit is divided in the ratio of (capital × time).

Given:

• Capital ratio A : B = 4 : 5
• Time: A = 9 months, B = 9 months

So time is same, only capital matters:

Profit ratio = 4 : 5

Total profit = 22000

Total parts = 4 + 5 = 9

A’s share:

4/9​×22000=9777.78≈9778

$$Last\; updated\; question\; NS\; on\; 10\; MAY\; 2026$$

Explanation

Explanation

Ratio boys : girls = 9 : 11
Total students = 80

Total parts = 9 + 11 = 20

Each part = 80 ÷ 20 = 4

Girls = 11 parts:

$$11\times 4=44$$

$$Last\; updated\; question\; NS\; on\; 10\; MAY\; 2026$$