Final answer:
To determine the total debit card purchases for Country A in 2010, we must reverse calculate the 33% increase that led to the $1.8 trillion total in 2011. By dividing $1.8 trillion by 1.33, we find that the 2010 total was approximately $1.35 trillion.
Step-by-step explanation:
The total Country A debit card purchases in 2010 can be calculated by recognizing that the 2011 value of $1.8 trillion represents a 33% increase from the 2010 value. To ascertain the total debit card purchases in 2010, we need to find the base value before the 33% increase. This base value plus 33% of it equals $1.8 trillion.
To represent this mathematically, let x be the total purchases in 2010. Thus, we can write the equation:
x + 0.33x = $1.8 trillion.
Combining like terms gives us:
1.33x = $1.8 trillion.
We can find x by dividing both sides of the equation by 1.33:
x = $1.8 trillion / 1.33.
Carrying out the division gives us:
x = approximately $1.3533834586 trillion.
The total Country A debit card purchases in 2010 were therefore approximately $1.35 trillion.