Q. The difference between the place value and the face value of 6 in the numeral 856973 is
a) 973
b) 6973
c) 5994
d) none of these.
Q. Each side of equilateral triangle is 6 cm. Its altitude is
a) 6√3
b) 3√3
c) 2√3
d) √3
Q. The length, breadth and height of a box are respectively 14 m, 12 m, 13 m. The length of the greatest rod that can be put in it is
a) 22.31 m
b) 22.56 m
c) 20 m
d) 19.5 m
Q. A solid spherical ball of radius 4cm is melted to form spheres of radius 2cm each. The number of spheres so formed is
a) 8
b) 9
c) 10
d) 16
Q. If cosA+ cos2A =1, then what is 2(sin2A + sin4A) equal to?
a) 4
b) 2
c) 1
d) 1/2
Q. The LCM of two numbers is 2376 while their HCF is 33. If one of the two numbers is 297, then the other number is
a) 216
b) 264
c) 642
d) 792
Q5. If a + b= 2m2 , b + c = 6m, a + c = 2, where m is a real number and a <= b <= c, then which one of the following is correct?
A) 0 <= m <= 1/2
B) -1<= m <= 0
C) 1/3 <= m <=1
D) 1 < m <= 2
Soln: Adding all the given equations we get, 2a + 2b + 2c = 2m2 + 6m + 2 >>> a + b + c = m2 + 3m + 1.
Therefore, a = m2 - 3m + 1, c = - m2 + 3m + 1 and b = m2 + 3m - 1.
Given, a<=b >>> m2 - 3m + 1 <= m2 + 3m - 1 >>> 2 <= 6m >>> m >= 1/3.
Given, b<=c >>> m2 + 3m - 1 <= - m2 + 3m + 1 >>> m2 <= 1 >>> m <= 1.
So, 1/3 <= m <= 1.
Q9. If x:y=1:3, y:z=5:k, z:t=2:5 and t:x=3:4, then what is the value of k?
Soln: Adding all the ratios, (x*y*z*t)/(x*y*z*t)=(1*5*3*2)/(3*k*5*4).
>>> 1=30/(60k) >>> K=1/2.