Hey there,

Following is my response and worked solutions:

Q13

Theres **Missing info** in question. Question is as follows:

It takes 60 painters 12 days to paint a school. How many painters are required to paint the same school in 20 days?

Logically , the possible answers to this question are (1) or (2). Reason being that less painters would be required to paint the same school in a longer duration.

The principle behind this kind of "Rate" question is to determine the 'work rate' (i.e. how much or what portion of the school is painted by a painter in day? ). The same goes with another typical example, to determine how much of the container or tank is filled up with water or any liquid in 1 day.

Worked Solution:

60 painters -> 12 days -> 1 whole school

60 painters -> 1 day -> (1/12) school

1 painter -> 1 day -> (1/720) school

1 painter -> 20 days -> (1/36) school

36 painters -> 20 days -> (36/36) school

Ans: **36** painters (1)

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Q15

Refer to attached figure in question.

In Triangle FKE:

Angle FEK = d (as given)

Angle EFK = a + c {Exterior Angle of triangle = Sum of Interior Opposite Angles}

Angle EKF = b + e {Exterior Angle of triangle = Sum of Interior Opposite Angles}

Hence, a + b + c + d + e = **180°** (2)

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Trust this helps.

Do let me know again if there's further clarification.

Cheers,

Edward