In a class there were 28 boys and some girls. In a test the mean score obtained by the boys was 12.5 while that obtained by the girls was 14.5. If the overall average was 13.1, what was the total number of students in the class?

According to question ,we can say that
From equation ?. x⁴ = 398 + 227 = 625
? x⁴ = 5⁴

From equation ?. y² = 346 - 321 = 25
? y² = 5²

But, Feb 2004 not included because we are calculating from March 2004 to March 2005. So it has 1 odd day only.

∴ The day on 6^th March, 2005 will be 1 day beyond the day on 6^th March, 2004.

Given that, 6^th March, 2005 is Monday.

∴ 6^th March, 2004 is Sunday (1 day before to 6^th March, 2005).

Couldn't be determined, since the total amount of money is not given in either of the case

Given that a /b = b/c
? b² = ac
? a⁴ : b⁴ = a⁴ : a² c² = a² : c²

Given, A = 6 km/h, B = 3 km/ h
According to the formula, Average speed = 2AB/(A + B)
? Required average speed = 2 x 6 x 3/(6 + 3)
= 36/9 = 4 km/h

Given that, W + D = 6 ...(i)
[ w = Time taken while walking and
D = Time taken while driving ]
From Eq. (i)
5 +D = 6
? D = 1
2D = 2 x 1 = 2
? He will take 2 h to drive both ways.

175760 = 2⁴ x 5 x 13 ³
= 2³ x 2 x 5 x 13³
To make perfect cube, it must be divided by 2 x 5 = 10

On comparing it with ax² + bx + c = 0 , we get a = 1, b = p, c = q
The roots of the equation x² + px + q = 0 are equal if
b² - 4ac = 0
? p² - 4q = 0 ? p² = 4q.
Thus , required answer is option B .

Let the volume be x³ and 27x³
? Their edges are x and 3x

Now Ratio of their surface area = 6x² : 54x² = 1 : 9