Simplification
- (5.5)3 – (4.5)3 is equal to :
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(5.5)3 – (4.5)3
= (5.5 – 4.5)3 + 3 × 5.5 × 4.5 (5.5 – 4.5)
= (1)3 + 74.25 (1)
= 1 + 74.25 = 75.25Correct Option: D
(5.5)3 – (4.5)3
= (5.5 – 4.5)3 + 3 × 5.5 × 4.5 (5.5 – 4.5)
= (1)3 + 74.25 (1)
= 1 + 74.25 = 75.25
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3√ 72.9 is equal to : 0.4096
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3√ 72.9 = 3√ 729000 0.4096 4096 3√ (90)3 = 90 (16)3 16 = 45 = 5.625 8 Correct Option: B
3√ 72.9 = 3√ 729000 0.4096 4096 3√ (90)3 = 90 (16)3 16 = 45 = 5.625 8
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3√8 ÷ √ 100 ×3√125 is equal to : √16 49
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On simplification,
Expression = 2 × 7 × 5 4 10 = 7 = 1 3 4 4 Correct Option: B
On simplification,
Expression = 2 × 7 × 5 4 10 = 7 = 1 3 4 4
- The sum of the cubes of the numbers 22, –15 and –7 is equal to
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Here, 22 – 15 – 7 = 0
We know that
a3 + b3 + c3 = 3abc,
if a + b + c = 0
∴ (22)3 + (–15)3 + (–7)3
= 3 × 22 × (–15) (–7) = 6930Correct Option: A
Here, 22 – 15 – 7 = 0
We know that
a3 + b3 + c3 = 3abc,
if a + b + c = 0
∴ (22)3 + (–15)3 + (–7)3
= 3 × 22 × (–15) (–7) = 6930
- The least number to be subtracted from 16800 to make it a perfect square is
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∴ Required number = 159
16800 – 159 = 16641
and √16641 = 129Correct Option: C
∴ Required number = 159
16800 – 159 = 16641
and √16641 = 129