Answer:
9
Step-by-step explanation:
The diagram showing the three pieces of paper of three digit in which two of the letters were covered can be seen below.
From the diagram; we have;
243 , 1_7 , _26
Assuming the covered digits are _
The sum is 826.
i.e
243 + 1_7 + _26 = 826
The objective is to determine the sum of the two unknown digits
So; we need to think about what number can we add put in 1_7 to determine the covered digit in _26
From ; 1_7 , we have the choice to pick from 0 - 9
Assuming the covered digit is 0; let's check if we are right
So; 243 + 1<u>0</u>7 + _26 = 826
350 + _26 = 826
_26 = 826 - 350
_26 = 476
So; the covered digit is in the position of 4 , but it doesn't tally together
i.e 426 is not the same as 476, which makes our assumption to be wrong.
Let consider the covered digit to be 5 for example.
So; 243 + 1<u>5</u>7 + _26 = 826
400 + _26 = 826
_26 = 826 - 400
_26 = 426
The covered digit is in the position of 4
SO;
<u>4</u>26 = 426
Here , our assumption is right.
As such , the covered digits are 5 and 4
The sum of the two covered digits are = 5 + 4 = 9