Decimal Fraction - Study Mode

[#66] $$frac{{{{left( {3.63}
ight)}^2} - {{left( {2.37}
ight)}^2}}}{{3.63 + 2.37}}$$ xa0 xa0is simplified to :
Correct Answer

(A) 1.26

Explanation

Solution: Given expression : $$frac{{left( {{a^2} - {b^2}}
ight)}}{{left( {a + b}
ight)}}$$ xa0,xa0where a = 3.63, b = 2.37 $$eqalign{
& = frac{{left( {a - b}
ight)left( {a + b}
ight)}}{{left( {a + b}
ight)}} cr
& = left( {a - b}
ight) cr
& = 3.63 - 2.37 cr
& = 1.26 cr} $$

[#67] (0.75 × 4.4 × 2.4) ÷ 0.6 = ?
Correct Answer

(C) 13.2

Explanation

Solution: Given expression : = 7.92 ÷ 0.6 = 79.2 ÷ 6 = 13.2

[#68] Solve : 1576 ÷ 45.02 + 23.99 × $$sqrt {255} $$xa0 = ?
Correct Answer

(B) 420

Explanation

Solution: Given expression : = 1576 ÷ 45.02 + 23.99 × $$sqrt {255} $$ = 1575 ÷ 45 + 24 × $$sqrt {256} $$ = 35 + 24 × 16 = 35 + 384 = 419 $$ approx $$ 420

[#69] Solve : $${left( {frac{{0.05}}{{0.25}} + frac{{0.25}}{{0.05}}}
ight)^3} =, ?$$
Correct Answer

(C) 140.6

Explanation

Solution: $$eqalign{
& {left( {frac{{0.05}}{{0.25}} + frac{{0.25}}{{0.05}}}
ight)^3} cr
& = {left( {frac{5}{{25}} + frac{{25}}{5}}
ight)^3} cr
& = {left( {frac{1}{5} + 5}
ight)^3} cr
& = {left( {frac{{26}}{5}}
ight)^3} cr
& = {left( {5.2}
ight)^3} cr
& = 140.608 approx 140.6 cr} $$

[#70] 0.04 x 0.0162 is equal to:
Correct Answer

(B) 6.48 x 10 -4

Explanation

Solution: 4 x 162 = 648. Sum of decimal places = 6. So, 0.04 x 0.0162 = 0.000648 = 6.48 x 10 -4