The speed of boat A is 2 km/h less than the speed of the boat B. The time taken by boat A to travel a distance of 20 km downstream is 30 min more than time taken by B to travel the same distance downstream. If the speed of the current is 1/3rd of the speed of the boat A, what is the speed of boat B?


A) 4

B) 6

C) 12

D) 10

E) 8

Correct Answer:
E) 8

Description for Correct answer:
Let the speed of boat B x + 2 km/hr

The speed of boat A is x kh/hr.

Speed of the current = \( \frac{1}{3} \times x = \frac{x}{3} km/hr \)

Accroding to question,

\( \frac{20}{x+\frac{x}{3}} \) - \( \frac{20}{(x+2)+\frac{x}{3}} \)

= \( \frac{30}{(60} \)

\( \frac{20 \times 3}{4x} - \frac{20 \times 3}{4x+6} = \frac{1}{2} \)

\( \frac{4x+6-4x}{4x \left(4x+6\right) } = \frac{1}{120}\)

\( \frac{6}{16x^{2}+24x} = \frac{1}{120} \)

\( 16x^{2}+24x-720=0 \)

\( 2x^{2}+3x-90=0 \)

\( 2x^{2}+15x-12x-90=0 \)

\( x \left(2x+15\right)-6 \left(2x+15\right)=0 \)

\( \left(x-6\right) \left(2x+15\right)=0 \)

x = 6

Hence, the speed of boat B = x + 2 = 6 + 2 = 8 km/hr

Part of solved LIC AAO questions and answers : Exams >> Bank Exams >> LIC AAO








Comments

No comments available




Similar Questions
1). A and B started a business by investing Rs.18,000/- and Rs.24,000/- respectively. At the end of 4th month from the start of the business, C joins with Rs.15,000/-. At the end of 8th month B quits at which time C invests Rs.3000/- more. At the end of 10th month B rejoins with the same investment. If profit at the end of the year is Rs.12,005/-, what is B's share of profit?
A). Rs. 4,000/-
B). Rs. 4,440/-
C). Rs. 4,360/-
D). Rs. 4,900/-
E). Rs. 3,920/-
-- View Answer
2). What is the difference between the total number of students who have enrolled for course on C++ and SQL together from college S and the total number of students who have enrolled for the same courses together from college R?
A). 134
B). 116
C). 128
D). 104
E). 96
-- View Answer
3). The total number of students who have enrolled for the course on Coco SD from colleges P and R together is what percent more than the total number of students who have enrolled for the same course from college S?
A). \( 11\frac{10}{17} \%\)
B). \( 11\frac{4}{17} \% \)
C). \( 12\frac{9}{11} \% \)
D). \( 10\frac{10}{19} \% \)
E). \( 9\frac{10}{19} \% \)
-- View Answer
4). What is the respective ratio between the total number of students who have enrolled for course on Java and SQL together from college P and the total number of students who have enrolled for the same courses together from college S?
A). 2 : 1
B). 3 : 1
C). 3 : 2
D). 5 : 3
E). 4 : 3
-- View Answer
5). Out of the total number of students who have enrolled for C++. 60% were able to pass the exam. If the respective ratio between the number of students from Colleges P, Q, R and S who were able to pass the exam for C++ was 3 : 4 : 2 : 3, what is the number of students who were able to pass the exam for C++ from college Q?
A). 200
B). 420
C). 340
D). 300
E). 400
-- View Answer


6). Out of the total number of students who have enrolled for course on Linux, 42% are females. If out of the total number of female students, who have enrolled for course on Linux, 20% are from college Q, how many male students from college Q have enrolled for the same course ?
A). 161
B). 174
C). 153
D). 126
E). 149
-- View Answer
7). \( 1810 / 24.05 \times 7.95 +11.02 \times 18.88 = ? - 306 \)
A). 1025
B). 1225
C). 1115
D). 1255
E). 1175
-- View Answer
8). \( 2775 \times 160/ \sqrt{?} = 5550 \)
A). 6400
B). 5625
C). 900
D). 1600
E). 2025
-- View Answer
9). \( 24.98^{2} \times 16.02^{2} \div \left(7.98 \times 15.04\right) \times 38.93 = 130 \times ?^{2} \)
A). 25
B). 45
C). 40
D). 30
-- View Answer
10). \( 71.98\% of 1200 + 35.06\% of 270 = ?\% of 600 \)
A). 140
B). 125
C). 120
D). 135
E). 160
-- View Answer