Find the average of the series : 312, 162, 132, 142 and 122?
A. 194
B. 174
C. 162
D. 186
Average = (312 + 162 + 132 + 142 + 122)/5 = 870/5 = 174
A. 194
B. 174
C. 162
D. 186
Average = (312 + 162 + 132 + 142 + 122)/5 = 870/5 = 174
A. 40
B. 80
C. 120
D. 200
Let the numbers be 3x, 4x and 5x.
Then, their L.C.M = 60x. So, 60x = 2400 or x = 40.
The numbers are (3 * 40), (4 * 40) and (5 * 40).
Hence, required H.C.F = 40.
A. 120
B. 260
C. 240
D. 220
Explanation with best method.
5 Steps
1.Data:
Train station platform= 36Sec
Standing platform = 20Sec
Speed of train = 54km/hr
2.Required:
Length of platform= x=???
3.Formula:
X+length of train/Train station platform
4.Solution: first for terms
Speed = 54 ×1000m/3600sec = 15 m/Sec.
Length of the train = (15 m/Sec × 20Sec = 300 m.
Let the length of the platform be x metres.
Now, x + 300m /36Sec= 15 m/Sec
x+300m= 15m/Sec×36Sec
x + 300m = 540m
x= 540m-300m
x = 240 m.
5.Result:
Length of platform=x=240m
A. 864 cm2
B. 648 cm2
C. 486 cm2
D. 468 cm2
Explanation:
a3 = 1728 => a = 12
6a2 = 6 * 12 * 12 = 864
A. 6 min
B. 12 min
C. 19 min
D. 10 min
Explanation:
1/8 + 1/24 = 1/6
6 * 2 = 12
A. Rs. 350
B. Rs. 390
C. Rs. 252
D. Rs. 316
Explanation:
Savings % = (100 – 65) % = 35 %
Saving = 35 % of Rs. 720
= Rs(35/100 ×720) = Rs. 252
A. 10%
B. 10.25%
C. 10.50%
D. None of these
Let the sum be Rs. 100. Then, S.I. for first 6 months = Rs. ( 100 X 10 X 1/100 X 2 ) = Rs. 5. S.I. for last 6 months = Rs. ( 105 X 10 X 1/100 X 2 ) = Rs. 5.25. So, amount at the end of 1 year=Rs.(100 + 5 + 5.25) = Rs. 110.25 Effective rate = (110.25 – 100) = 10.25%.