Let the total time be x mins. Part filled in first half means in x/2 = 1/40 Part filled in second half means in x/2 = (1/60 + 1/40) = 1/24

Now, (x/2 * 1/40) + (x/2 + 1/24) = 1

x/2 * (1/40 + 1/24) = 1

x/2 * 1/15 = 1

x = 30 mins

Total volume of water displaced = (4 x 50) m3 = 200 m3.

Rise in water level = 200/(40*20) m = 0.25 m = 25 cm

Let the number of students in rooms A and B be x and y respectively.

Then, x - 10 = y + 10      x - y = 20 .... (i)

     and x + 20 = 2(y - 20)      x - 2y = -60 .... (ii)

Solving (i) and (ii) we get: x = 100 , y = 80.

The required answer A = 100.

Originally, let the number of seats for Mathematics, Physics and Biology be 5x, 7x and 8x respectively.

Number of increased seats are (140% of 5x), (150% of 7x) and (175% of 8x).

the required time be x seconds.

More metres, More time (Direct Proportion)

0.128 : 25 :: 1 : x       0.128x = 25 x 1

Le the required time be x seconds.

More metres, More time (Direct Proportion)

Let the average age of the whole team by x years.

11x - (26 + 29) = 9(x -1)

11x - 9x = 46

2x = 46

x = 23.

So, average age of the team is 23 years

Let their present ages be 4x, 7x and 9x years respectively.

Then, (4x - 8) + (7x - 8) + (9x - 8) = 56

20x = 80

x = 4.

Their present ages are 4x = 16 years, 7x = 28 years and 9x = 36 years respectively.

Let the ten's and unit digit be x and

8

respectively.

x

Then,

10x +

8

A's 1 hour's work =

1

;

4

(B + C)'s 1 hour's work =

1

;

3

(A + C)'s 1 hour's work =

1

.

2

(A + B + C)'s 1 ho 

Let original length = x and original breadth = y.

Decrease in area

= xy -

80

x

x

90

y

Speed of train relative to man = (60 + 6) km/hr = 66 km/hr.

   =

66 x

5

m/sec

18

   =

Let the amount taxable purchases be Rs. x.

The area goes up as the square of the diameter, so the new area is (1.5)^2 times the old area, = 2.25 times larger. But the question is about the increase. The increase is 125%

Money collected = (59.29 x 100) paise = 5929 paise.

Number of members = 5929 = 77.

Let the middle digit be x. Then, 2x = 10 or x = 5. So, the number is either 253 or 352,

Since the number increases on reversing the digits, so the hundred's digit is smaller

than the unit's digit. Hence, required number = 253.