Number of ways of (selecting at least two couples among five people selected) = (⁵C₂ x ⁶C₁)

As remaining person can be any one among three couples left.

Required probability = (⁵C₂ x ⁶C₁)/¹⁰C₅
= (10 x 6)/252 = 5/21

My fahter's mother's only daughter-in-law is my father's wife i.e. my mother. My mother's daughter is my sister. My sister's father is my father.

The China-sponsored Asian Infrastructure Investment Bank (AIIB) has approved $160 million loan for Andhra Pradesh – 24×7 Power for All project with an objective to strengthen power transmission and distribution system in the state. It is the first credit from the AIIB for an Indian project. The power project is co-financed by the World Bank (WB). The project is part of the Government of India’s Power for All Program that was launched in 2014 to provide an efficient, reliable and affordable electricity supply to all consumers across selected states within five years from the start of implementation of the program in each state.

Yielding the floor :  The speaker of the Lok sabha can ask a member of the house to stop speaking and let another member speak.

Crossing the floor:  Passing between the member addressing the House and the Chair which is considered breach of Parliamentary etiquette.

Point of Order:  A Member of Parliament may raise a point of order if he feels that the proceedings of' the House do not follow the normal rules. The presiding officer decides whether the point of order raised by the member should be allowed.

Calling Attention Motion:  With the prior permission of the Speaker, any member of the Parliament may call the attention of a Minister to a matter of urgent public importance. The Minister may make a brief statement about the matter or he may ask for time to make a statement later.

1/10 + 1/15 = 1/6 x 3 = 1/2

1 - 1/2 = 1/2

1/10 + 1/15 - 1/x = 1/2

x = 8.57 min

Let 1 woman's 1 day work = x.

Then, 1 man's 1 day work = x/2 and 1 child's 1 day work  x/4.

So, (3x/2 + 4x + + 6x/4) = 1/7

28x/4 = 1/7 => x = 1/49

1 woman alone can complete the work in 49 days.

So, to complete the work in 7 days, number of women required = 49/7 = 7.