If the basalt at the top of the ancient valley below Vulcan's Throne yields a radiometric date (K-Ar) of 15,000 years, and the lowermost flows in the same valley yield an age of 1.2 million years, what is the rate of basalt filling in the valley in feet per million years (ft/my).

feet/million year

Step-by-step explanation:

We are given that

Elevation of top of basalt in valley =4100 feet

Elevation of bottom of basalt in valley =2100 feet

Age of top of basalt in valley=15000 years

Age of bottom of basalt in valley=1.2 million years=

We have to find the rate of basalt filling in the valley in feet per million yeas

Rate of basalt filling in the valley=

Rate of basalt filling in the valley=

Rate of basalt filling in the valley=feet/million year

answer: 25 is the correct answer

step-by-step explanation:

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.