d) if a : b = 3 : 6 and b : c = 15 : 7,then a : b : c =

To solve this problem, we need to find the ratio a : b : c. We already know a : b and b : c, so we can use these to find the final ratio.

Step 1: Simplify the ratio a : b. The ratio a : b = 3 : 6 can be simplified to 1 : 2, because both 3 and 6 can be divided by 3.

Step 2: Use the simplified ratio a : b and the given ratio b : c to find a : b : c. We know a : b = 1 : 2 and b : c = 15 : 7. The common term here is 'b'. To combine these ratios, 'b' should be the same in both ratios.

To make 'b' the same in both ratios, we can multiply the first ratio by 15 and the second ratio by 2. This gives us a : b = 15 : 30 and b : c = 30 : 14.

Step 3: Combine the ratios. Now that 'b' is the same in both ratios, we can combine them to get a : b : c = 15 : 30 : 14.

So, the ratio a : b : c is 15 : 30 : 14.