Let x be the digit in the tens place and y be the digit in the ones place.
so, the digit is xy
<span>
The ten's digit of a two digit number is 1 more than 4 times the units' digit.
</span>x = 4y + 1
<span>63 is subtracted from the number, the order of the digits is reversed
</span>10x + y - 63 = 10y + x
9x - 9y = 63
x = 4y + 1 ------------ (1)
9x - 9y = 63 ---------- (2)
Sub (1) into (2)
9(4y + 1) - 9y = 63
36y + 9 - 9y = 63
27y = 63 - 9
27y = 54
y = 2 ------- sub into (1)
x = 4(2) + 1 = 9
x = 9, y = 2
The number is 92
Let would be the annual interest rate such that,
I = P x r^t
For the 1st
160.67 = (2000) x r*8/12 ; r = 0.02277
The second case is just the same.
To find the mean, aka average, we must add all the values of the table, then divide that sum by the number of values
