In three coloured boxes - Red, Green and Blue, 108 balls are placed. There are twice as many balls in the green and red boxes combined as there are in the blue box and twice as many in the blue box as there are in the red box. How many balls are there in the green box ?

Correct Answer: 11 days

Explanation:

Let 'n' number of days it take to complete.

 

we know that sum of n number= n/2[2a+(n-1)d]
where a=20,d=1;
n/2[2x20+(n-1)1]=275
n[n+39]=550
n 2 + 39n - 550 = 0
  n 2+ 50n - 11n - 550 = 0
(n-11) (n-50) = 0
n-11 = 0;
n = 11(Days).

Correct Answer: 240 gms

Explanation:

The nine pieces consist of 8 smaller equal pieces and one half cake piece.
Weight of each small piece = 15 g.
So, total weight of the cake = [2 x (15 x 8)]g = 240 g.

Correct Answer: Any one pair of A and B, B and C or C and A is sufficient

Explanation:

From the given data,

Let the two gits of a number be x & y

A) x + y = 15

 

B)  x 2 - y 2 = 45

(x+y) (x - y) = 45

 

C) x - y = 3

From any 2 of the given 3 statements, we can find that 2 digit number as 

2x = 18 => x = 9

=> y = 6

Hence, 2 digit number is 96.

 

Any one pair of A and B, B and C or C and A is sufficient to find.

Correct Answer: 5.008 x 10^3 kms

Explanation:

We know that, any decimal number when multiplied by the multiples of 10, the decimal point moves to right the number of zeroes in the multiplying number.

 

For example :: 

0.0410 x 100 = 4.10 (Number of zeros in 100 are 2. So, the decimal point in 0.0410 moves two places to the right and becomes 4.10.)

 

Similarly, here in the option C) 5.008 x 10^3 kms it makes 5008 kms as the number of zeros in 10^3  i.e,  1000 are 3 and 5.008 becomes 5008.

Correct Answer: 2015736

Explanation:

Divisibility rule for 24 is the number should be divisible by 3 and 8. As we know that 24 = 3 x 8

Now, 

Divisibility rule for 3 :

If the sum of the digits of a number is divisible by 3, then the number is divisible by 3.

 

Divisibility rule for 8 :

The last three digits of a number should be divisible by 8.

Hence, check for the given options,

A) 37804 => 804 is not divible by 8.

C) 36718 => 718 is not divible by 8.

D) 53810 => 810 is not divible by 8.

B) 2015736 => 736 is divisble by 8 and sum 2 + 0 + 1 + 5 + 7 + 3 + 6 = 24 which is divisible by 3.

 

Hence, 2015736 is divisible by 24.

Correct Answer: 50

Explanation:

15 girls are absent => b = 2(g-15)...... eqn...(1)

45 boys are absent => g - 15 = 5(b-45).....eqn...(2)

=> g = 5(b-45) + 15

=> b = 2((5(b-45)+15)-15)

=> b = 2(5b - 225 + 15 - 15)

=> b = 2(5b-225)

=> b = 10b - 450

=> 9b = 450

=> b = 50

so from equation(2)

g - 15 = 5(b - 45)

=> g - 15 = 5(50-45)

=> g - 15 = 5(5)

=> g = 25 + 15

=> g = 40

Therefore, the number of boys = 50 and girls = 40

Correct Answer: is described generally, not using a formal definition

Explanation:

In geometry, we can define plane as a flat surface with no thickness.

The surface extends with no ends.

A plane does not have any edges even if we draw it on paper with edges, it does't mean it has edges.

 

Hence, A plane is an undefined term because it is described generally, not using a formal definition.

Correct Answer: 1

Explanation:

The product of a number and its reciprocal is always equals to 1.

 

For Example : Let the number be 4.

Now, its reciprocal is 1/4

Hence, required product = 4 x 1/4 = 1.

 

Now, take the number as -15.

Then its reciprocal is -1/15

Required product = -15 x -1/15 = 1.

 

Hence, the product of a number and its reciprocal is 1.

Correct Answer: 1/7

Explanation:

Multiplicative inverse is nothing but a reciprocal of a number. 

It is defined as one of a pair of numbers that when multiplied with another number equals the number 1.

Multiplicative inverse or reciprocal of 7 is 

7 x n = 1

=> n = 1/7.

 

Hence, Multiplicative inverse or reciprocal of 7 is  1/7.

Correct Answer: Complimentary angles

Explanation:

Complimentary angles are those two angles whose sum is 90 whereas two angles whose sum is 180 are called Supplementary angles.