**Quantitative Aptitude Tests IBPS CWE RRB Clerks,SBI PO Mains,SSC**

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

1.958 833 733 658 608 (?)

(A) 577

(B) 583

(C) 567

(D) 573

(E) None of these

2.11 10 18 51 200 (?)

(A) 885

(B) 1025

(C) 865

(D) 995

(E) None of these

3.25 48 94 186 370 , (?)

(A) 738

(B) 744

(C) 746

(D) 724

(E) None of these

4. 14 24 43 71 108 (?)

(A) 194

(B) 154

(C) 145

(D) 155

(E) None of these

5. 144 173 140 169 136 (?)

(A) 157

(B) 148

(C) 164 9

(D) 132

(E) None of these

**Directions (Q. 6-9): The following question is Q accompanied by three statements A, B and C. You have to determine which statement (s) is/ are necessary/ sufficient to answer the question.**

6. What is the speed of the train?

I. The train crosses 300 meters long platform in 21 seconds.

II. The train crosses another stationary train of equal length in 2 [math]\frac{1}{19}[/math]seconds.

III. The train crosses a signal pole in 4 [math]\frac{3}{9}[/math] seconds

(A) Only I and II

(B) Only II and either I or III

(C) Only I and either II or III

(D) Only III and either I or II

(E) None of these

7. A boat takes 4 hours to go upstream from x to y and back downstream from y to x on a river .What is the speed of the boat on still water?

(A) The distance between x and y is 6 km.

(B) The boat takes 2 hours less to go downstream than to go upstream.

(C) The speed of the current is 2 kmph.

(A) Only A and B are sufficient

(B) Only A and C are sufficient

(C) Any two of the three are sufficient

(D) B alone is sufficient

(E) All even together are not sufficient

8. In how many days can a work be completed by X, Y and Z together?

(A) Ratio of the work efficiencies of X, Y and Z is 3 : 2 : 1.

(B) Z works for 5 days and leaves the job and the remaining work is done by X and Y together in 5 days.

(C) 60% of the work is done by X alone in 6 days.

(A) Any two of them

(B) Only A and C together

(C) Only B

(D) Either B alone or A and C together

(E) None of these

9. In how many days can 10 women finish a work?

I. 10 men can complete the work in 6 days.

II. 10 men and 10 women together can

III. If 10 men work for 3[math]\frac{3}{7}[/math] days and thereafter 10 women replace them, the remaining work is completed in 4 days.

(A) Only I and II

(B) Any two of the three

(C) Only I and III

(D) Only II and III

(E) None of these

**Key with Explanations**

1-B; The pattern of the number series is:

958 – 833 = 125;

833 – 733 = 100

733-658 = 75;

658-608 = 50

∴ ? = 608 – 25 = 583

2-D; The pattern of the number series is:

11 x1 -1 =10;

10×2-2 = 18;

18×3-3 = 51;

51 x 4 – 4 = 200 ;

200 x 5 – 5 = 995

3-A; The pattern of the number series is:

25 x 2 – 2 = 50 – 2 = 48

48 x 2 – 2 = 96 – 2 = 94

94×2-2 = 188-2 = 186

186×2-2 = 372-2 = 370

370 x 2 – 2 = 740 – 2 = 738

4-B; The pattern of the number series is:

14 + 10 = 24

24 + 19 (=10 + 9) =43

43 + 28 (=19 + 9) =71

71 +37 (=28+ 9) = 108

108 + 46 (=37+ 9) = 154

5-E; The pattern of the number series is :

144 + 29 = 173;

173-33 = 140;

140 + 29 = 169;

169-33 = 136;

136 + 29 = 165

6-C;

7-C; From (A) and (C) let speed of boat in still water be x.

[math]\frac{6}{2+x}[/math]+ [math]\frac{6}{2-x}[/math]=4

6(x – 2) + 6(x + 20) = 4 x (x^{2} – 4)

x = -1, 4 (Negative value) From (A) and (B) let time taken to go upstream be y hour, (y – 2) + y = 4 implies y = 3 hours.

Speed in still water [math]\frac{\frac{6}{1}+ \frac{6}{3}} {2}[/math]=4Kmph

From (B) and (C),

Speed in still water = 2 x[math]\frac{3+1}{3-1}[/math]=4 Kmph

8-D; From statements (A) and (C), X alone can do the work in 6x [math]\frac{5}{3}[/math]=10 days

Y alone can do the work in 10x [math]\frac{3}{2}[/math]=15 days

Z alone can do the work in 30 days.

Hence, all three together can do the work in 5 days.

From statement (B) alone, Z works for 5 days and the remaining work is done by X and Y together. Hence, all three together can do the work in 5 days.

Hence B alone or A and C together is sufficient.

9:B