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1. If “*” is called “+”, “/” is called “*”, “-” is called “/”, “+” is called “-”. 40/20 – 5 * 10 + 5 = ?
A. 170
B. 160
C. 150
D. 165
Answer: Option D
Explanation:
Given : [latex]\frac{40}{20}[/latex] – 5 * 10 + 5 = ?
Substituting the coded symbols for mathematical operations, we get,
40 * [latex]\frac{20}{5 }[/latex] +10 – 5 = ?
40 * 4 + 10 – 5 = ?
160 + 10 – 5 = ?
170 – 5 = 165
2. If Suresh distributes his pens in the ratio of 1/2 : 1/4 : 1/5 : 1/7 between his four friends A, B, C and D, then find the total number of pens Suresh should have?
A. 153
B. 150
C. 100
D. 125
Answer: Option A
Explanation:
Here, A : B : C : D = [latex]\frac{1}{2}[/latex] : [latex]\frac{1}{4 }[/latex] : [latex]\frac{1}{5 }[/latex] : [latex]\frac{1}{7 }[/latex]
1) L.C.M of 2, 4, 5, 7 is 140
2) Find the number of pens each friend received --------- (To find no. of pens each friend has, multiply the ratio with the L.C.M. calculated)
A = ([latex]\frac{1}{2}[/latex]) x 140 = 70
B = ([latex]\frac{1}{4 }[/latex]) x 140 = 35
C = ([latex]\frac{1}{5 }[/latex]) x 140 = 28
D = ([latex]\frac{1}{7 }[/latex]) x 140 = 20
3) Total number of pens = (70 x + 35 x + 28 x + 20 x) = 153 x
Minimum number of pens (x) = 1
Therefore, total number of pens = 153 pens
3. When folded into two equal halves a rectangular sheet had a perimeter of 48cm for each part folded along one set of sides and the same is 66cm when folded along the other set of sides. Find the area of the sheet.
A. 1584
B. 1120
C. 792
D. 1320
Answer: Option B
Explanation:
Let the sheet be folded along its breadth and its perimeter = 48cm
Therefore, ([latex]\frac{L}{2 }[/latex] + b) = 48 …... (i)
Now, let the sheet be folded along its length, and the perimeter = 66cm
(l + [latex]\frac{b}{2 }[/latex])= 66 …... (ii)
Solving (i) and (ii), we get,
l = 56cm, b = 20cm
Area = l*b
Area = 1120 c[latex]{m}^{2 }[/latex]
4. A clock was set right at 2 p.m. It gains 5 seconds in 3 minutes, and it indicates 8.30 a.m. the next morning, then the true time is:
A. 8.00 a.m.
B. 7.45 a.m.
C. 8.15 a.m.
D. 7.30 a.m.
Answer: Option A
Explanation:
Time elapsed from 2 p.m. to 8.30 a.m. = 18 hours 30 minutes = 1110 minutes.
Now, 3 minutes and 5 seconds of the given clock is 3 minutes of the correct clock.
Therefore, 1110 minutes of this clock is [latex]\frac{(1110 * 3)}{(37/12) }[/latex] minutes of the correct clock.
= 1080 minutes = 18 hours of the correct clock
Hence, the correct time is 8 a.m.
5. Find the number of times the hour hand and the minute hand of a clock are at right angle in a day.
Answer: Option D
Explanation:
In 12 hours, the hands of a clock are at right angle 22 times.
Hence in a day they are at right angle 44 times.