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Q:

A and B take part in 100 m race. A runs at 5 kmph. A gives B a start of 8 m and still beats him by 8 seconds. The speed of B is:

A) 5.15 kmph	B) 4.14 kmph
C) 4.25 kmph	D) 4.4 kmph

Answer & Explanation Answer: B) 4.14 kmph

Explanation:

A's speed = (5*5/15)m/sec = (25/18)m/sec

Time taken by A to cover 100 m = (100*18/15)sec = 72sec

Time taken by B to cover 92 m = (72 + 8) = 80 sec.

B's speed =(92/80*18/5)kmph =4.14kmph

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Filed Under: Races and Games

Q:

In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:

A) 21/46	B) 1/5
C) 3/25	D) 1/50

Answer & Explanation Answer: A) 21/46

Explanation:

Let , S - sample space E - event of selecting 1 girl and 2 boys.

Then, n(S) = Number ways of selecting 3 students out of 25

= $25 C_{3}$

= 2300.

n(E) = $10 C_{1} \times 15 C_{2}$ = 1050.

$\therefore$ P(E) = n(E)/n(s) = 1050/2300 = 21/46

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Filed Under: Probability

Q:

In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:

A) 21/46	B) 1/5
C) 3/25	D) 1/50

Answer & Explanation Answer: A) 21/46

Explanation:

Let S be the sample space and E be the event of selecting 1 girl and 2 boys.

Then, n(S) = Number ways of selecting 3 students out of 25

= $25 C_{3}$ = 2300.

n(E)= $10 C_{1} * 15 C_{2}$ = 1050.

P(E) = n(E)/n(s) = 1050/2300 = 21/46

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Filed Under: Probability

Q:

A sum of Rs.1550 was lent partly at 8% p.a. simple interest. The total interest received after 3 years was Rs.300. The ratio of the money lent at 5% to that lent at 8% is :

A) 5:8	B) 6:7
C) 16:15	D) 17:18

Answer & Explanation Answer: C) 16:15

Explanation:

let the sum lent at 5% be Rs.x and that lent at 8% be Rs.(1550-x). then,

Interest on x at 5% for 3 years + interest on (1550-x) at 8% for 3 years = 300

$\frac{x * 5 * 3}{100} + \frac{(1500 - x) * 8 * 3}{100} = 300$

x=800

Required ratio = x : (1550-x) = 800 : (1550-800) = 800 : 750 = 16 : 15

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Filed Under: Simple Interest
Exam Prep: Bank Exams
Job Role: Bank PO

Q:

The present worth of Rs.1404 due in two equal half-yearly instalments at 8% per annum. Simple interest is:

A) 1320	B) 1300
C) 1325	D) 1200

Answer & Explanation Answer: C) 1325

Explanation:

Required Sum = PW of Rs.702 due 6 months hence + PW of Rs.702 due 1 year hence

= Rs.[ (100 x 702) / (100+(8 x 1/2)) ] + [ (100 x 702) / (100+(8 x 1)) ]

= Rs.1325

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Filed Under: True Discount

Q:

A has to pay Rs.220 to B after 1yr. B asks A to pay Rs.110 in cash and defer the payment of Rs.110 for 2 yrs. A agrees to it. If the rate of interest be 10% per annum in this mode of payment:

A) A gains Rs.11	B) There is No gain or loss
C) A losses 7.43	D) A gains Rs. 7.34

Answer & Explanation Answer: D) A gains Rs. 7.34

Explanation:

A has to pay = Present worth of Rs220 due 1yr hence

= Rs.[(220 x 100)/100+(10 x 1)] = Rs.200

A actually pays = Rs.110+PW of Rs.110 due 2 yrs hence

= [110+(110 x 100)] / [100+(10 x 2)] = Rs.192.66

So, A gains Rs. (200-192.66) = Rs.7.34

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Filed Under: True Discount

Q:

Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 4000 for 2 years at 10% per annum. The sum placed on simple interest is:

A) Rs.1550	B) Rs.1650
C) Rs,1750	D) Rs.1850

Answer & Explanation Answer: C) Rs,1750

Explanation:

C.I.= Rs.[4000*(1+10/100)^2-4000]

=Rs.840

sum=Rs.(420 * 100)/3*8=Rs.1750

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Filed Under: Compound Interest
Exam Prep: Bank Exams
Job Role: Bank PO

Q:

The least number of complete years in which a sum of money put out at 20% compound interest will be more than doubled is:

A) 3	B) 4
C) 5	D) 6

Answer & Explanation Answer: B) 4

Explanation:

$P {(1 + \frac{20}{100})}^{n} > 2 P \Leftrightarrow {(\frac{6}{5})}^{n} > 2$

$(\frac{6}{5} \times \frac{6}{5} \times \frac{6}{5} \times \frac{6}{5}) > 2$

so, answer is 4 years

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Filed Under: Compound Interest
Exam Prep: Bank Exams
Job Role: Bank PO

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