MCQ
$\sqrt{10}\times\sqrt{15}$ is equal to:
- ✓$5\sqrt6$
- B$6\sqrt5$
- C$\sqrt{30}$
- D$\sqrt{25}$
✓
Answer
Correct option: A.
$5\sqrt6$
$10 = 5 \times 2$
$15 = 5 \times 3$
$\therefore\sqrt{10}\times\sqrt{15}=\sqrt{5\times2}\times\sqrt{5\times3}$
$=\sqrt{5}\times\sqrt{2}\times\sqrt{5}\times\sqrt3$
$=\big(\sqrt5\times\sqrt5\big)\times\sqrt2\times\sqrt3$
$=5\sqrt6$
Hence, correct option is $(a).$
$15 = 5 \times 3$
$\therefore\sqrt{10}\times\sqrt{15}=\sqrt{5\times2}\times\sqrt{5\times3}$
$=\sqrt{5}\times\sqrt{2}\times\sqrt{5}\times\sqrt3$
$=\big(\sqrt5\times\sqrt5\big)\times\sqrt2\times\sqrt3$
$=5\sqrt6$
Hence, correct option is $(a).$
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