The ratio between the speeds of two Bullet trains is 7: 8. If the second Bullet train runs 420 kms in 4 hours, then the speed of the first train is:  Select.
A) 89.25 km/hr.	B) 37.25 km/hr.	C) 90.25 km/hr.	D) 94.25 km/hr.	E) 91.875 km/hr.
Let the speed of two bullet trains be 7x and 8x km/hr.   Then, 8x = (420/4)= 
<gadget id="calculator">(420/4)</gadget>
<output>105</output>
105   x= (105/8)= 
<gadget id="calculator">(105/8)</gadget>
<output>105/8 = around 13.125</output>
13.125   Hence, speed of first bullet train= (7 x 13.125) km/hr = 91.875 km/hr.   91.875 km/hr.
<result>E</result>
The ratio between the speeds of two Bullet trains is 7: 8. If the second Bullet train runs 420 kms in 4 hours, then the speed of the first train is: