Mary used
411 of the rope to tie some presents. She threw away
611 of the remaining rope. As a result, she had 490 cm of the rope left. How much rope did Mary have at first? Give your answer in cm.
Fraction of the rope left after tying some presents
= 1 -
411=
711 Fraction of the remaining rope left after throwing away
= 1 -
611=
511
Fraction of the total rope left
=
711 ×
511=
35121
Length of the rope at first = 121 u
Length of the rope left = 35 u
35 u = 490
1 u = 490 ÷ 35 = 14
Length of the rope at first
= 121 u
= 121 x 14
= 1694 cm
Answer(s): 1694 cm