**Directions (Q. 1-5): What value should come in place of question mark (?) in the following number series?**

**1. 124 215 342 511 ? 999**

1) 695

2) 625

3) 728

4) 806

5) 573

**2. 516 256 126 61 28.5 ?**

1) 12.25

2) 16.75

3) 14.25

4) 20.20

5) 18.7

**3. 7 21 50 109 ? 467**

1) 198

2) 228

3) 372

4) 402

5) 275

**4. 18 82 118 134 138 ?**

1) 132

2) 198

3) 125

4) 138

5) 92

**5. 5 22 103 406 ? 2422**

1) 1516

2) 1298

3) 1136

4) 1602

5) 1213

**6. A mixture of milk and water contains 7% water. What quantity of pure milk should be added to 12 litres of mixture to reduce water to 4%?**

1) 5 litres

2) 6 litres

3) 7 litres

4) 8 litres

5) 9 litres

**7. Two candles of the same height are lighted at the same time. The first is consumed in 6 hours and the second in 4 hours. Assuming that each candle burns at a constant rate, in how many hours after being lighted, was the first candle was twice the height of the second?**

1) 3.5 hrs

2) 2 hrs

3) 4 hrs

4) 3 hrs

5) 2.5 hrs

**8. Three friends Anil, Ravi and Sumit jog around a circular park and complete round in 21, 18 and 24 minutes respectively. In how many hrs will all the three meet again at starting point?**

1) 8 hrs

2) 8.4 hrs

3) 6.5 hrs

4) 7.5 hrs

5) 9 hrs

**9. With the help of the digits 1, 2, 3 and 4 find the sum of all 4 – digits numbers provided that the digits are not repeated.**

1) 66,660

2) 6500

3) 40375

4) 100013

5) None of these

**10. A, B and C can do a piece of work in 20, 30 and 100 days respectively. If A worked alone on the first day, B worked alone on the second day, C worked alone on the third day, A worked alone on the fourth day, and so on, then in how many days the work got completed?**

1) 29 days

2) 28 days

3) 31 1/2 days

4) Can't be determined

5) None of these

Answers

1. 3

The series is

5^3 – 1 = 124

6^3 – 1 = 215

7^3 – 1 = 342

8^3 – 1 = 511

9^3 – 1 = 728

10^3 – 1 = 999

Required answer = 728

2. 1

The series is

3. 2

The series is

4. 4

The series is

5. 5

The series is

6. 5; The quantity of pure milk to be added

= {12 * (7 - 4)}/4 = 9 litres

7. 4

h = height of candles

The first candle consumed in 6 hours and the second in 4 hours."

first candle shortens by h/6 each hour

second candle shortens by h/4 each hour

height of first candle after t hours = h - th/6 = h(1 - t/6)

height of second candle after t hours = h - th/4 = h(1 - t/4)

h(1 - t/6) = 2h(1 - t/4)

(1 - t/6) = 2(1 - t/4)

1 - t/6 = 2 - t/2

t/2 - t/6 = 1

6t - 2t = 12

t = 12/4 = 3 hours

8. 2

Required time = LCM of 21, 18, 24 min = 504 mins = 8.4 hrs

9. 1;

1 × 2 × 3 × 4 = 24 numbers, it mean at every place digits

will occur six times.

Sum of one column = 6 ( 1 + 2 + 3 + 4) = 60

Hence, sum of all the numbers

= 60 × (100 + 101 + 102 + 103)

= 60 × 1111 = 66660

10. 3

A's, B's and C's 1 day work = 1/20 + 1/30 + 1/100

Total 3 day's work = 28/300

Total 30 day work = 280/300

Remaining work = 20/300 = 1/15

Now A's 1 day work = 1/20

Then remaining work = (1/60)/(1/30) = 1/2

Now, B's then B complete the remaining work in 1/2

Total number of days = 31 1/2 days.