Quantitative Aptitude For Competitive Examinations (English) 7th Edition

126. what will be unit’s digit in the result of the expression 3

126. what will be unit’s digit in the result of the expression 3

^{65}* 6^{53 }*9^{5}?
A. 6 B. 2 C.3 D.7

Ans: 2

127. if x and y throw a pair of dice alternately .x wins if the throws 4 before y throws 5 and y wins. If she throws 5 before x throws 4. Find y’s chance of winning if x makes the first throw

A.1/3 B.1/2 C.5/11 D.5/12

Ans: Not Available please comment below the answer for others help, will be updated then.

128. A train 1200m long crosses a platform in 1.5 min at a speed of 54 kmph . what is the length of the platform?

A.150m B.120m C.175m D.100m

Ans: A

129. a cow gives 4 litres of milk daily ,but this is only (1/3)

^{rd}of what a herd of cows gives daily.if 24 litres of milk is collected in 2 days ,the number of cows in the herd is
A. 6 B. none of the mentioned options C. 3 D. 2

Ans: 3

130. if (x+1/X) = 6, the value of (X

^{5}+1/x^{5}) is
A.7302 B. 5473 C. 6726

Ans: . Shortcut : let (x+1/x) = a

Then (x

^{5}+1/x^{5}) = a^{5}-5a^{3}+5a
So answer : 6726

131. two trains of the same length but with different speeds pass a static pole in 4 sec and 5 sec respectively. In what time will they cross each other .when they are moving in the same direction?

A.3.22 sec B. 4.98 sec C. 4.44 sec D. 4.22 sec

Ans: Same direction : relative speed is s1-s2

Opposite Direction: relative speed is : s1+s2

S1= l/4

S2=l/5

Same direction: time= distance/speed

=2l/s1-s2;

Substitute s1 and s2 values in above equation, we get 40 seconds

But no option contains this answer.

Assuming that given question is for opposite direction then we get answer as 4.44 sec.

So choose 4.44 seconds as answer

132. A person covers a distance in 40 min .if he runs at a speed 45 kmph on a average . find the speed at which he must run to reduce the time of journey to 30 min

A. 40 kmph B. 30 kmph C. 50 kmph D. 60 kmph

Ans: 40 * 45 = 30 * x;

Find x value .

Ans: 60

133. a sum of RS. 5000 was divided among P,Q and R in the ratio 2:3:5. If the amount of RS.500 was added to each ,what will be their new ratio ?

A. 3:4:6 B. 3:5:4 C. 3:4:5 D. 2:3:4

Ans: Divide 5000 in the ratio of 2:3:5 then 1000, 1500, 2500

Add 500 to 1000, 1500 and 2500 then 1500: 2000: 3000

3:4:6

134. there are two vessels which are filled with milk of two quantities worth RS.10 per litre and RS. 11 per litre .in what approximate ratio these two be mixed to get a new quality of milk of worth RS.10.6 litre?

A. 1:3 B. 1:2 C. 2:3 D. 2:1

Ans: 10 * x + 11 * y = (x+y) * 10.6 ( Assume x & y quantity in vessels 1 & 2 respectively )

Solve for x/y = 2:3

135. A man walking with a speed of 5kmph reaches his target 5min late. If he walks at a speed of 6kmph, he reaches on time. Find the distance of the target from this house.

2.5km 3km 1.5km 4km

Ans: distance= 5 * (t+5/60)

Distance = 6* t

Equate above two equations

t=5/12

distance = 6*(5/12) = 2.5 km

136. If m=3-2 , then the value of -(1/ ) is:

1 2 2 -1

Ans: . -(1/ ) = x

Squaring on both sides

m+1/m-2=x

^{2}
so x=2

137. If radius of circle is increased by 5% then the percentage increase in its area is:

8.25% 10.25% 25% 9.32%

Ans: let’s original radius is 100

Then new radius is 105

Original area= Pi*100*100 = x

New area is = Pi*105*105 = y

%increase= ((y-x)/x)*100

Ans= 10.25

138. What is the total number of ways of selecting at least one object from 2 sets of 10 distinctly different objects?

2

^{20}-1 100 (2^{10}-1)^{2}120
Ans: Not Available please comment below the answer for others help, will be updated then.

139. Read the info given below and answer the question that follow:

(a$b)=(a+b)/2

(a&b)=(a

^{2}-b^{2})
(a?b)=(a-b)/2

What will be the value of((a$b)/(a&b))

^{2}-(a$b)(a?b) at a =4 and b=6?
95/16 65/16 31/16 81/16

Ans: 81/16

140. Determine the speed of train of length 180cm if it crosses a pole in 5 sec.

190kmph 135.8kmph 129.6kmph 150.5kmph

Ans: 129.6 kmph

141. A certain number of men can do a work in 75days. If there were 6more men, it could be completed in 15 days less. How many men were there in the beginning?

30 men 27 men 24 men 21 men

Ans: x * 75 =(x+6) * 60

Find x.

Ans= 24