Question

Which of the following option(s) is/are true for $a,b$ and $c$ marked on the number line below.

• A. $a=3,b=7,c=14$
• B. Estimation of $a\times b\times c$ to the nearest hundreds is $300$
• C. Estimation of $a\times b\times c$ to the nearest hundreds is $320$
• D. $a=9,b=5,c=7$

Answer 1

Answer: (B), (D)

$a=9,b=5,c=7$

Starting from 3, if we make $a$ hops to the right, we arrive at 12.
$\Rightarrow a=12-3=9$

Starting from 12, if we make $b$ hops to the left, we arrive at 7.
$\Rightarrow b=12-7=5$

Starting from 7, if we make $c$ hops to the right, we arrive at 14.
$\Rightarrow c=14-7=7$

$\therefore a=9,b=5,c=7$

Now, $a\times b\times c=9\times 5\times 7=315$

Its tens digit is 1, which is less than 5. So, we keep the hundreds digit as it is and replace the tens digit and ones digit by 0 to get the rounded off number to the nearest hundreds.

Hence, rounded off number = 300.