20 +63 without rewriting find the sum using mental math
2 answers:
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If a person bought 8 items and each item was priced at $4, that means the total amount spent was $32.
The person received 8 dollars in change. This means that the person payed 8 dollars more than what they spent. Well, we just found out how much they spent, so we can find out how much money the person gave the vendor.
Let p = amount of money paid by the person.
The person gave the vendor $40.
Answer:
I assume you know Arithmetic Progression .
so, we have to find the first and last 4-digit number divisible by 5
first = 1000 , last = 9990
we have a formula, = a + (n-1)d
here, is the last 4-digit number divisible by 5.
n is the number of 4-digit even numbers divisible by 5
d is the common difference between the numbers, which is 10 in this case
a is the first 4-digit number divisible by 5
9990 = 1000 + (n-1)*10
899 = n-1
n = 900
Hence, there are 900 4-digit even numbers divisible by 5