When you divide a number by 10^n (i.e. 1 followed by n zeroes), you move the decimal point separator n places to the left (assuming that integers have the decimal separator at the end, as in 2 = 2.0).
So, the first option is to divide 18 by 100. So, we start from 18=18.0 and move the separator two places to the left:
The second option is to divide 8 by 10. So, we start from 8=8.0 and move the separator one place to the left:
The third option is to divide 18 by 10. So, we start from 18=18.0 and move the separator one place to the left:
So this is the correct option.
Answer:
8 years
Step-by-step explanation:
Let age of father be f
age of John be j
age of Alice be a
John's father is 5 times as old as John. We can write:
f = 5j
John is twice as old as Alice. We can write:
j = 2a
or
a = j/2
SUM OF ALL OF THEIR AGES (after 2 years) will be 58. We can write:
f+2 + j+2 + a+2 = 58
This becomes:
f + j + a + 6 = 58
f + j + a = 52
Now, we replace third equation with the first two (in bold) and get:
So John is 8 years old