#IDETICEDU #MATH #RRBNTPCQUIZ

Mathematics Quiz For RRB NTPC

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1. In a school the number of boys and girls are in the ratio of 4:7. If the number of boys are increased by 25% and the number of girls are increased by 15%. What will be the new ratio of number of boys to that of girls?
a) 100:131
b) 100:151
c) 100:161
d) 100:181
e) None of these

2. When 40% percent of a number is added to another number the second number increases to its 20%. What is the ratio between the first and second number?
a) 2:1
b) 1:2
c) 2:3
d) 3:4
e) None of these

3. Two candles of same height are lighted at the same time. The first is consumed in 6 hours and second in 4 hours. Assuming that each candles burns at a constant rate, in how many hours after being lighted, the ratio between the first and second candles becomes 2:1?
a) 1 hour
b) 2 hour
c) 3 hour
d) 4 hour
e) None of these

4. An employer reduces the number of his employees in the ratio of 7:4 and increases their wages in the ratio 3:5. State whether his bill of total wages increases or decreases and in what ratio.
a) increases 20:21
b) decreases 21:20
c) increases 21:22
d) decreases 22:21
e) None of these

5. A vessel contains milk and water in the ratio of 4:3. If 14 litres of the mixture is drawn and filled with water, the ratio changes to 3:4. How much milk was there in the vessel initially?
a) 24
b) 32
c) 40
d) 48
e) None of these

6. The income of Neha and Hitesh are in the ratio of 4:5 and their expenditure is in the ratio of 2:3. If each of them saves 2000, then find their income.
a) 4000, 6000
b) 4000, 5000
c) 5000, 4000
d) 5000, 6000
e) None of these

7. The average height of 15 students is calculated as 75. But later it was found that the height of 1 student wrongly entered as 35 instead of 38 and another as 46 instead of 63.The correct average is
A)71
B)73
C)75
D)76

8. The average of 5 consecutive number is 58.Find the first number ?
A)55
B)56
C)57
D)58

9. An article is sold at 25% profit. Had it been sold at Rs30 less then there would have been a loss of 25%. What was the cost price (in Rupees)?
A) 75
B) 45
C) 60
D) 90
E) 72

10. A man gets Rs.620 for every day for his work . If he earns Rs.12400 in a month of 31 days . Find how many days did he work?
A) 10 days
B) 21 days
C) 20 days
D) 18 days
E) 15 days

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Answer

1. Answer – c) 100:161
Explanation :
Boys = 4x and girls = 7x
Ratio = 4x*125/100 : 7x*115/100 = 100:161

2. Answer – b) 1:2
Explanation :
(40/100)*a + b = (120/100)*b
a:b = 1:2

3.Answer – c) 3 hour
Explanation :
Let height of both candles is ‘h’ and let after t times ratio between the height be 2:1
h – t*h/6 : h – t*h/4 = 2:1
t = 3

4. Answer – b) decreases 21:20
Explanation :
Let initial employees be 7x and then 4x similarly initial wages be 3y and then 5y
so total wage = 21xy initially and then 20xy
so wages decreases and ratio = 21:20

5. Answer & Explanation
Answer – b) 32
Explanation :
milk = 4x and water = 3x
milk = 4x – 14*4/7 and water = 3x – 14*3/7 + 14
4x – 8: 3x + 8 = 3:4
X = 8, so milk = 8*4 = 32 litres

6. Answer – b) 4000, 5000
Explanation :
4x – 2y = 2000 and 5x – 3y = 2000.
X = 1000, so income = 4000 and 5000

7.Answer – D)76
Explanation :
{(15*75)-(35+46)+(38+63)} / 15 = (1125 –
81 + 101) / 15
= 1145/15 = 76.33 = 76

8. Answer – B)56
Explanation :
X+x+1+x+2+x+3+x+4 = 58*5 = 290
5x+10 = 290
X = 290 – 10/5 = 280/5 = 56

9. Option C
Solution:
Profit = 25% = 1/4
CP………….SP
4………………5
Loss 25%= CP SP
. 4…..3
In both SPs, difference = 5-3 = 2
2=30
1=15
4=60

10. Option C
Solution:
Number of days = 12400/620 = 20 days

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