- The ratio of the milk to water in a mixture is 4 : 3. 21 liter of mixture is taken out and 8 liter of milk and 14 liter of water is added in mixture, so that new ratio of milk to water becomes 320 : 17, then find initial quantity of milk in the mixture ?
84 liters35 liters63 liters80 liters72 litersOption A

Let quantity of milk and water in the mixture = 4x and 3x respectively

(4x – 21 * 4/7 + 8)/(3x – 21 * 3/7 + 14) = 20/17

4x – 4/3x + 5 = 20/17

x = 21

Initial quantity of milk in the mixture = 4x = 4 * 21 = 84 liters - A alone can do 40% of work in 8 days and B alone can do 30% of work in 12 days. If efficiency of C is 50% more than A, then find in how many days A, B and C together will be completed 90% of work ?
5 days8 days12 days6 days4 daysOption D

Total days required to complete the work by A = 8/40 * 100 = 20

total days required to complete the work by B = 12/30 * 100 = 40

LCM of 20 and 40 = 40

efficiency of A = 40/20 = 2

efficiency of B = 40/40 = 1

efficiency of C = 2 * 150/100 = 3

days required = 40/6 * 90/100 = 6 days - The ratio of present age of A and B is 3 : 4. If the ratio of age of A after 6 years and age of B before 4 years is 6 : 5, then find the age of B after 4 years ?
42 years25 years26 years28 years40 yearsOption D

Let the present age of A and B = 3x and 4x

3x + 6/ 4x – 4 = 6/5

15x + 30 = 24x – 24

x = 6

the age of B after 4 years = 4x + 4 = 28 years - A man goes from a place A to B at a speed of 12 km/hr and returns from B to A at a speed of 18 km/hr. What is the average speed for the whole journey ?
12 km/hr24 km/hr14 km/hr14 2/5 km/hr15 2/5 km/hrOption D

Average speed = 2xy /x + y

= 2 * 12 * 18/12 + 18 = 14 2/5 km/hr - A boat covers 12 km upstream and 18 km downstream in 3 hours while it covers 36 km upstream and 24 downstream in 6 1/2 hours, what is the speed of stream ?
5 km/hr4 km/hr6 km/hr2 km/hr8 km/hrOption D

12/x – y + 18/x + y = 3

36/x – y + 24/x + y = 13/2

let x – y = a, x + y = b

12/a + 18/b = 3

36a + 24/b = 13/2

By multiplying ‘3’ in equation (i)

36/a + 54/b = 9

36/a + 24/b = 13/2

30/b = 9 – 13/2

b = 12

36/a + 9/2 = 9

36/a = 9/2

a = 8

x – y = 8

x + y = 12

2x = 20

x = 10

y = 2 - Directions : What will come in place of questions marks (?) in the following number series ?

345, 358, 375, ?, 417, 446380382392394396Option D

The series is, (+ 13), (+ 17), (+ 19), (+ 23), (+ 29), - 5, 11, 35, 143, 719, ?
42404319446549784565Option B

The series is, ( * 2 + 1), ( * 3 + 2), ( * 4 + 3), ( * 5 + 4), ( * 6 + 5), - 20, 18, 38, 56, 94, ?
155100120125150Option E

The series is, (20 + 18), (18 + 56), (56 + 94) - 35, 40, 55, 80, 115, ?
145180160172165Option C

The series is, (+ 5), (+ 15), (+ 25), (+ 35), (+ 45), - 35, 18, 19, 30, ?, 157.5
6462589686Option B

The series is, ( * 5 + .5), (* 1 + 1), (* 1.5 + 1.5), (* 2 + 2), (* 2.5 + 2.5)