Question

ST

Problem number 26 of the Rhind Papyrus says:
Find a quantity such that when it is added to of itself
the result is a 15.

The modern day equation that models this problem is
x+x=15.

What is the solution to the equation?
O x = 10

x = 12


x = 15
x = 30

Answer 1

Explanation:

please make sure that fractions are still in the problem text after scanning it.

because they are missing here, and I have to guess around.

Basically the problem is

x + 1/a × x = 15

that means

ax + x = 15a

(a+1)x = 15a

x = 15a/(a+1)

for a = 2 (so, 1/2 x is added to x), we get

x = 15×2/3 = 30/3 = 10

for a = 4 (1/4 of x is added to x), we get

x = 15×4/5 = 60/5 = 12

these are also the first 2 answer options. so, please pick the one that fits the complete problem definition.

the 3rd and 4th answer options are nonsense anyway, as when you add something greater than 0 to x and get 15, then the initial x cannot be already 15 or even bigger.