20% raise of price followed by a discount of 25% of the raised portion will
increase the price by 10%
decrease the price by 5%
increases the price by 15%
increases the price by 15%
The sum of the ages of two brothers, having a difference of 8yr between them, will double after 10 yr. What is the ratio of the age of the younger brother to that of the elder brother?
7 : 11
3 : 7
8 : 9
8 : 9
The ratio of two numbers is 3 : 4 and their LCM is 180. The second number is
60
45
90
90
Out of 30 teachers of a school, a teacher of age of 60 yr retired. In his place another teacher of age 30 yr was appointed. As a result, the mean age of the teacher will
decrease by 6 months
decrease by 1 yr
remain same
remain same
Average age of A, B and C is 84 yr. When D joins them the average age becomes 80 yr. A new person E, whose age is 4 yr more than D, replaces A and the average of B, C, D and E becomes 78 yr. What is the age of A?
60 yr
70 yr
80 yr
50 yr
C.
80 yr
Average age of A, B and C is 84 yr.
∴ A + B + C = 3 x 84 = 252 ...(i)
∵ A + B + C + D = 4 x 80 = 320
252 + D = 320
D = 320 - 252 = 68
According to the question,
E = D + 4
= 68 + 4 = 72
∴ D + E = 68 + 72 = 140 ...(ii)
Now, average age of B, C, D and E = 78
B + C + D + E = 78 x 4 = 312 ...(iii)
Putting the value of (D + E) from Eq. (ii) and Eq.(iii), we get
B + C + 140 = 312
⇒ B + C = 312 - 140 = 172 ...(iv)
From Eqs (i) and (iv), we get
A + 172 = 252
⇒ A = 252 - 172
A = 80
Hence, the present age of A is 80 yr.
By selling an article for ₹ 450, a man loses 10%. The gain or loss per cent if he sells it for ₹ 540 is
loss 8%
gain 9%
loss 9%
loss 9%
A man loses of his money and after spending 80% of the remainder, he is left with ₹ 159. How much did he have at first?
₹ 500
₹ 800
₹ 1000
₹ 1000
A gun is fired at a distance of 1.34 km from Geeta. She hears the sound after 4 s. The speed at which sound travels is
335 m/s
330 m/s
300 m/s
300 m/s
If I walk at 5km/h, I miss a train by 7 min. However, if I walk at 6 km/h I reach the station 5 min before the departure of the train. The distance between my house and the station is
6.5 km
7 km
6 km
6 km
The compound interest on ₹ 1800 at 10% per annum for a certain period of time is ₹ 378. Find the time (in yr).
2.8
3.0
2.5
2.5