11 Players can make 10 matches.

If 20 players are there,  there can be 19 matches in total.

The doctor is the mother of the ‘son’. whereas his father is not a doctor.

That’s a ‘super-heavy’ mom and baby!

Baby weighs 25 kg

If Mother’s weight = M; Baby = B, Dog = D:

1. M + B + D = 170
2. M = (B + D) + 100

= > B + D = 35   (a)

3. D = B * 0.4  (Dog weighs 60% less than the baby => Dog’s weight is 40% (0.4) of the baby’s weight.)
(a) & (3) => B + D = B + 0.4B = 1.4 B = 35

=> B = 25

D = 10 and Mother, 135

X-Q’s-ME => Excuse Me

The question seems faulty. It says “25% passed both the tests” and then asks “percentage of those students who passed the first test and also passed the second test“. “Passing the first test and also the second test” is the same as passing both the tests. Hence, the answer is given directly in the question itself!

She may be doing anything!

May be sleeping…
May be helping any of the other sisters (except the one who is reading novel) …
May be reading newspaper or some book…
May be doing some other household task – say, cleaning rooms…
May be exercising…
Or may be simply watching other sisters doing their things…!

(The “expected answer” seems to be ‘playing chess with sister 3’ (on the assumption that chess needs two players), but NOT necessarily so. One can play chess on her own, playing both sides by herself.)

John is 41 now, So, he will be 43 in two years from now.

Let current age be X. Then four times the age four years from now will be (X + 4) x 4. Similarly, 5 times the age five years from now will be (X + 5) x 5.
Hence, we have:

(X + 4) x 4 + (X + 5) x 5 = 10X

=> 4X + 16 + 5X + 25 = 9X + 41 = 10X

=> X = 41.

You are not one, but TWO…!!

See-saw…!

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