Area of circular disc = Pi*(10 cm)^2
= 100 Pi
314 cm^2
Now rectangle of maximum area inside circle will be square of side length r*Sqrt2, where r is radius so
Area of square disc = (r*Sqrt2)^2
= 2r^2 = 2*(10cm)^2
= 200 cm^2
So area of remaining disc = 314-200 cm^2
114 cm^2
Option 7)
First two digits of the code make the sequence
12, 23, 34, 45, So next will be 56
similarly third letter of the code make the sequence
Z, Y, X, W so next will be V
And fourth letter of the code make the sequence
A, B, C, D so next will be E
so code is
56VE
Tap A can fill a tank in 4 hours whereas tap B and tap C can empty it in respectively 12 hours and 16 hours separately. All the 3 tap are opened with tank empty. After 2 hours tap B is closed, after how much time of closing of B, tank will be filled completely.
OPtion
1) 4 hrs 13 min 20 sec
2) 3 hrs 54 min 18 sec
3) 4 hrs 15 min 30 sec
4) 3 hrs 46 min 40 sec
5) 5 hrs 2 min 20 sec
6) 5 hrs 10 min 40 sec
7) 6 hrs 12 min
8) 5 hrs 40 min
9) 2 hrs 58 min 20 sec
10)5 hrs 10 min 20 sec
Solution
When all the 3 tap are opened the work of 1 hrs
= 1/4 - 1/12 - 1/16
= 12-4-3/ 48 = 5/48
Work of 2 hrs = 5/48 * 2 = 5/24 part
remaining work = 1- 5/24 = 19/24 part
After closing tap B,
the work of remaining 2 taps
per hr = 1/4 - 1/16 = 3/16
So extra hours required = (19/24)/3/16
= 19*16/ 24*3 = 38/9 hrs
Therefore
4 hrs & 2/9 hrs
4 hrs & (2*60)/9 min
4 hrs & 40/3 min
4 hrs & 13min & 1/3 min
Therefore
4 hrs & 13min & 20 sec
Option 1)
4, 15, 40, 85, 156, x
15-4 = 11
40-15 = 25
85-40 = 45
156-85 = 71
So
11, 25, 45, 71 is the next series
Now
25-11 = 14
45-25 = 20
71-45 = 26
12, 20, 26 is the series having common diff of 6
so next number is 26+6 = 32
So series is 11, 25, 45, 71, 71+32=103
So next = 259
The mean temperature of Monday to Wednesday was 37^0 C and that of Tuesday to Thursday was 34^0 C. If the temperature on Thursday was (4/5)th that of Monday, what was the temperature on Thursday?
OPtion
1) 34^0 C
2) 35.5^0 C
3) 37.5^0 C
4) 37^0 C
5) 38.5^0 C
6) 38^0 C
7) 33^0 C
8) 33.5^0 C
9) 36.5^0 C
10)36^0 C
Solution
M+T+W = 3*7 = 111
T+W+Th = 3*34 = 102
On subtraction we get
(M-Th) = 9
or
M - 4/5 M = 9
So M = 45
Therefore
Th = 4/5 M = 4/5* 45 = 36^0 C
Option 10)
The difference between a two-digit number and the number obtained by interchanging the digits is 36. What is the difference between the sum and the difference of the digits of the number if the ratio between the digits of the number is 1 : 2 ?
frank
"Numbers have life ; they are not just symbols on paper"