Question

Given that a:12=4:10 find the value of a.

Answer 1

A:12=4:10

The extremes are a and 10
The middles are 12 and 4

We know that PRODUCT OF MIDDLE = PRODUCT OF EXTREMES
a*10=12*4
a     = 48/10
a     = 4.8

Therefore, the value of a = 4.8

Answer 2

A/12= 4/10

Cross multiply: 12*4= a*10
⇒ a= 12*4/10= 4.8

Final answer: a= 4.8