Simplification and Approximation

A. 1/20
B. 1/5
C. 4
D. 10
Explanation:
(1.9 * 0.021) / (0.095 * 0.105) = (19 * 21 * 100) / (95 * 105) = 4

A. 125
B. 525
C. 25/64
D. 625
Explanation:
(25 * 25)/25 + 15 * 40 = 25 + 600 = 625.

A. 1
B. 27/98
C. 6/17
D. 27/17
Explanation:
By applying BODMAS rule.
51/4 * (19/17 / 49/6) / 19/3
= 51/4 * ( 19/17 * 6/49) * 3/19 = 27/98

A. 9
B. 16
C. 8
D. 12
Explanation:
Applying BODMAS rule
= 7 + 1/2 of [8 – 4 / 2 * 3 – 2 + (4 + 2) – 2 * 2]
= 7 + 1/2 of [8 – 2 * 3 – 2 + 6 – 4]
= 7 + 1/2 of (2) = 8

A. 8/15, 9/13, 6/11
B. 8/15, 6/11, 9/13
C. 9/13, 6/11, 8/15
D. 6/11, 8/15, 9/13
Explanation:
The fractions considered are 8/15 9/13 6/11
To compare them we make the denominators the same. So the fractions are
(8 * 13 * 11)/2145, (9 * 15 * 11)/2145 and (6 * 15 * 13)/2145
1144/2145, 1485/2145 and 1170/2145
so in descending order the fractions will be
1485/2145, 1170/2145 and 1144/2145 i.e., 9/13 , 6/11 , 8/15

A. 3 * 2.75 * 2.75 * 2.75
B. 3 * 2.00 * 2.00 * 2.00
C. 3 * 2.75 * 0.75 * 2.75
D. 4.5 * 2.75
Explanation:
(2.75)3 – (2.00)3 – (0.75)3
a3 + b3 + c3 = (a + b + c)(a3 + b3 + c3 – ab – bc – ca)
If a + b + c = 0 then a3 + b3 + c3 = 3abc
Hence 2.75 – 2.00 – 0.75 = 0
So, (2.75)3 – (2.00)3 – (0.75)3
= 3 * 2.75 * 2 * 0.75 = 3 * 1.5 * 2.75
= 4.5 * 2.75

A. 11
B. 12
C. 14
D. 19
Explanation:
{20 – [7 – (3 -2)] + 1/3 (4.2)} / 1.4
=> [20 – (7 – 1) + 1.4] / 1.4
=> (20 – 6 + 1.4)/1.4 = 10 + 1 = 11

A. 55606
B. 55697
C. 55967
D. 73373
Explanation:
64309 – 8703 + 798 – 437 => 65107 – 9140 = 55967

A. 26
B. 26.26
C. 2.2
D. -22.22

A. 19
B. 28
C. 30
D. 37