darlingriyarai wrote:For a certain company, the ratio of the amount budgeted for research to the amount budgeted for production is 2 to 7 and the ratio of the amount budgeted for marketing to the amount budgeted for production is 1 to 5. What is the ratio of the amount budgeted for research to the total amount budgeted for research, production, and marketing?

A. 1 to 5
B. 2 to 5
C. 2 to 9
D. 5 to 14
E. 5 to 26

We can combine the 2 ratios to get a 3-part ratio. This requires a common term.

Given:
research/production = 2/7
marketing/production = 1/5

Both ratios share a production value. So, let's find equivalent ratios such that the production value is the same for both. We get:
research/production = 2/7 = 10/35
marketing/production = 1/5 = 7/35

Now that both ratios share the same production value (of 35), we can combine the ratios to get:
research:production: marketing = 10:35: 7

We want to find the ratio research : (research+production+marketing)
= 10 : (10+35+7)
= 10 : 52
= 5 : 26 [spoiler]= E[/spoiler]

Cheers,
Brent