If Mira was twice as heavy as she is, she would be 10 lbs lighter than her mother; if she were to lose 10 lbs, she would be 75% of her present weight. How much does Mira’s mother weigh?
- 60 lbs
- 70 lbs
- 80 lbs
- 90 lbs
- 100 lbs
The Usual Method
Let the weight of Mira be ‘x’ years and that of her mother be ‘y’ years.
…… Eq. 1
and …… Eq. 2
From Eq. 2,
Estimated Time to arrive at the answer = 45 seconds.
If 10 lbs is reduced from a weigh, than it becomes 75% of the original. Thus the reduction of 10 lbs is equivalent to 25%. Hence 100% is equal to 40 lbs. Thus Mira’s weight is 40 lbs and her mother’s weight is 90 lbs.
Estimated Time to arrive at the answer = 15 seconds.