Given :
Tammy saved nickels and pennies in a jar the ration of nickels to pennies was 2 : 5 .
To Find :
If there where 70 nickels in the jar how many coins are there in all.
Solution :
Let, number of pennies are x.
It is given that ratio of nickels to pennies is 2 : 5.
So, numbers of pennies are 175.
Therefore, total number of coins in the jar is, 175 + 70 = 245 coins.
We can rule out choices A and B since they have a negative slope.
We can rule out choice C because the y intercept is nowhere near 42.
The y intercept isn't clear, but if we draw a line so that it is as close as possible to all the points, then it hits around the 5 to 10 range, so 7 is a fairly good estimate. Choice D is the only answer choice left, so its the best estimate.
See the diagram below.
