Question

A rocket flies at a speed of $2.6\times {10}^7$ m/s . If the speed of a jet is $130000$ m/s, then the rocket's speed is _____ times the speed of the jet.

• A. 240
• B. 2400
• C. 200
• D. 2000

Answer 1

The correct option is C 200

$\frac{\text{Speed of the rocket}}{\text{Speed of the jet}}=\frac{2.6\times {10}^7}{130000}$

$=\frac{2.6\times {10}^7}{1.3\times {10}^5}$

$=\frac{2.6}{1.3}\times {10}^{7-5}$

$=2\times {10}^2=200$

Thus, the speed of rocket is 200 times that of the jet.