O and O' are the center of the two circles with radii 7cm and 9cm respectively. The distance between the centers is 20cm. If PQ be the transverse common tangent to the circles, which cuts OO' at X, what is the length of O'X in cm ?

Correct Answer: 54 min

Explanation:

If virus is K in 1hr i.e 60 min
then in 57 min it was K/2 as it doubles every 3 minutes
=> In 54 min it was K/4.
At 54 minutes it was K/4.

Correct Answer: 200 days

Explanation:

As given
200 cats kill 200 mice in 200 days
1 cats kill 1 mouse in 200 days
Then
8 cats kill 8 mice in 200 days.

Correct Answer: 9

Explanation:

3 divided by 1/3

=>  3 1 3

= 3 x 3/1 

= 9

Correct Answer: FALSE

Explanation:

Any integer 'i' can be written as i = i/1, which is a rational number. Clearly, 7/2,-5/4, etc... are rational numbers but they are not integers.

Hence, from the above analysis, every integer is a rational number but a rational number need not be an integer.

 

Therefore the given statement that 'Every rational number is an integer' is FALSE.

Correct Answer: 166 2/3 million

Explanation:

5% - 2% = 3%
=> 3% ------ 5 million bags
100% ---- ?
=> 166 2/3 million bags.

Correct Answer: 30

Explanation:

Then, A:B = 2:3 and B:C = 5:8
= (5 x 3/5) : (8 x 3/5) = 3:24/5
A:B:C = 2:3:24/5
= 10:15:24 => B = 98 x 15/49 = 30.

Correct Answer: z < x < y

Explanation:

x = ?8 - ?7 = 1/(?8 + ?7) and y = ?6 - ?5 = 1/(?6 + ?5) and z = ?10 - 3 = 1/(?10 + 3)

As (?8 + ?7) > (?6 + ?5), (?8 - ?7) < (?6 - ?5)

As (?10 + 3) > (?8 + ?7) > (?6 + ?5)

z < x < y.

Correct Answer: 620

Explanation:

Here in the question it is asked that 62 tens, which implies ten times of 62.

=> 62 x 10 = 620.

 

Hence, the value of 62 tens = 620.

Correct Answer: 4

Explanation:

To join 5 tables we require 4 joins.

Correct Answer: 7 & 24

Explanation:

7 boxes & 24 Balls.
Let, n = No. of boxes ; m = No. of fruits
3n+3 = m---------->(1)
4(n-1)= m---------->(2)
=>4n-4 = 3n+3;
=>4n-3n = 4+3
n = 7
Put n=7 in eqn(1)
=> 3(7)+3 = m
21+3 = m
m = 24;

Number of boxes = 7 and fruits = 24