AIEEE Questions

---

A Sound wave needs a medium for propogation. Hence, Sound cannot travel through a vacuum.

A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.

Given ratio = 1/2:2/3:3/4 = 6:8:9

1st part = 782 x 6/23 = Rs. 204.

Let Siya's age = x

Then Riya's age = 4x

But given Riya's age = 24

=> 4x = 24 => x = 6

Hence Siya's age = 6 yrs

=> The age difference = 24 - 6 = 18 yrs.

Argon is most the most abundant Rare Gas in the atmosphere. Its elemental symbol is Ar. 

The surface area of a cube = 6a2 =  6 side2

New  Surface area = 6 x 1.44a2

Therefore, 0.44a2a2x100 = 44%

Here in the given numbers 91 is a Composite number. Since it has factors of 7 and 13 other than 1 and itself.

Composite Numbers :

A composite number is a positive integer which is not prime (i.e., which has factors other than 1 and itself).

Examples :: 4, 6, 8, 12, 14, 15, 18, 20, ...

Let the total work be 'W'

As per the given information,

P can complete the work 'W' in 24 days.

=> one day work of P = W/24

And also given that,

The time taken by P to complete one-third of work is equal to time taken by Q to complete half of the work

=> PW/3 = QW/2

=> P's

1 day =    W/24

   ?    =      W/3

=>  ?  = 24W/3W  = 8

=> QW/2 = 8 days

=> Q alone can complete the work W in 16 days

=> P + Q can complete the work in

1/24 + 1/16 = 5/48

=> 48/5 days = 9 3/5 days.

Let work done by 1 man in i day be m

and Let work done by 1 boy in 1 day be b

From the given data,

4(5m + 3b) = 23

20m + 12b = 23....(1)

2(3m + 2b) = 7

6m + 4b = 7 ....(2)

By solving (1) & (2), we get

m = 1, b = 1/4

Let the number of required boys = n

6(7 1 + n x 1/4) = 45

=> n = 2.