Required distance is the LCM of 84 cm, 90 cm and 120 cm.
Thus,
Since, 84 = 2 × 2 × 3 × 7 = 22 × 3 × 7
90 = 2 × 3 × 3 × 5 = 2 × 32 × 5
and 120 = 2 × 2 × 2 × 3 × 5
= 23 × 3 × 5
∴ LCM = Product of each prime factor with highest power
= 23 × 32 × 5 × 7 = 2520
= 25 m 20 cm
Problems Based on Irrational Numbers
Find the largest number that will divide 398,436 and 542 leaving remainders 7, 11 and 15 respectively. Problems Based on Fundamental Theorem of Arithmetic