A. 144
B. 72
C. 36
D. none of these
Explanation:
200 % of x = 90
=> x = 9000/200 = 45
80 % of x = (80/100 ×45) = 36
A. ²²C₁₀
B. ²²C₁₀ + 1
C. ²²C₉ + ¹⁰C₁
D. ²²C₁₀ – 1
Explanation:
The total number of ways of forming the group of ten representatives is ²²C₁₀.
The total number of ways of forming the group that consists of no seniors is ¹⁰C₁₀ = 1 way
The required number of ways = ²²C₁₀ – 1
A. 7 years
B. 11 years
C. 18 years
D. 27 years
9 * 2 = 18 years
A. 9000
B. 9400
C. 9600
D. 9800
Explanation:
Greatest number of 4 digits is 9999. L.C.M of 15, 25, 40 and 75 is 600.
On dividing 9999 by 600, the remainder is 399. Required number = 9999 – 399 = 9600
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. -21
B. 1
C. 61
D. 21
Explanation:
a2 + b2 + ab = a2 + b2 + 2ab – ab
i.e., (a + b)2 – ab
from x2 – 9x + 20 = 0, we have
a + b = 9 and ab = 20. Hence the value of required expression (9)2 – 20 = 61.
A. 12 liters
B. 10 liters
C. 4 liters
D. 2 liters
Explanation:
70 * (10/100) = 7
Wine Water
87 1/2% 12 1/2%
87 1/2% ——- 63
12 1/2% ——-? => 9-7=2