Question

There were n signers of the Declaration of Independence. The oldest was Benjamin Franklin, who was y years old.

7 is 10% of y and n is 80% of y. How many signers were there?

Answer 1

Answer:

There were 56 signers.

Step-by-step explanation:

First, set up the two equations for the two situations we are given.

7 is 10% of y . . . . .(1):

$7 = \frac{10}{100}(y)$

n is 80% of y . . . . .(2):

$n = \frac{80}{100}(y)$

Now, solve for y in the 1st equation, and substitute y in the second equation to solve for n.

$7 = \frac{10y}{100}$

$700 = 10y$

$70 = y$

$n = \frac{80*70}{100}$

$n = \frac{5600}{100}$

$n = 56$

Answer 2

Answer:

• 56 signers

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7 is 10% of y, find y:

• 7 = 0.1y ⇒ y = 70

n is 80% of y, find n:

• n = 0.8y = 0.8*70 = 56