Let x, y and z be non-zero numbers. If x: y = 3 : 1 and y: z = 4:3, find (x + z) : (x + y). Please help me to solve this question with steps, thanks!orz

 15 : 16

Step-by-step explanation:

x : y              y : z

3 : 1              4 : 3

Find the LCM for both y's.  LCM = 4

     x : y                        y : z

3(4) : 1(4)                      4 : 3

 12 :  4                         4 : 3

-->    x : y : z = 12 : 4 : 3

 (x + z) : (x + y)

12 + 3 : 12 + 4

   15   :     16

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.