Question

Three pieces of timber 42m, 49m and 63m long have to be divided into planks of the same length.what is the greatest possible length each plank?

Answer 1

i think its the hcf of these 3 numbers and it is 7

Answer 2

The least possible number of planks is 7 m.

Step-by-step explanation:

Given : If three pieces of timber 42 m, 49 m and 63 m long have to be dividend into planks of the same length.

To find : What will be the least possible number of planks?

Solution :-

To find the least possible number which means the highest common factor of the numbers.

Prime factor of the numbers 42,49,63

$\sf~42=2\times 3\times 742=2×3×7$

$\sf~49=7\times 749=7×7$

$\sf~63=3\times 3\times 763=3×3×7$

The highest common factor of the numbers 42,49 and 63 is:-

$\sf{\underline{\red{HCF=7}}}$

Therefore, The least possible number of planks is 7 m.