Ian's and Kathy's monthly allowances were the same at first. Ian's allowance increased by 40% while Kathy's increased by 35%. Given that Ian's allowance would increase by another 35% if he had received $686 more from his mother, find the difference in the children's monthly allowances.
| |
Ian |
Kathy |
| Before |
1 u |
1 u |
| Change 1 |
+ 0.4 u |
+ 0.35 u |
| After 1 |
1.4 u |
1.35 u |
| Change 2 |
+ 0.49 u |
No change |
| After 2 |
1.89 u |
1.35 u |
Increase in Ian's allowance
= 40% x 1 u
=
40100 x 1 u
= 0.4 u
Increase in Kathy's allowance
= 35% x 1 u
=
35100 x 1 u
= 0.35 u
Increase in Ian's allowance if his mother gave another $686
= 35% x 1.4 u
=
35100 x 1.4 u
= 0.49 u
0.49 u = 686
1 u = 686 ÷ 0.49 = 1400
Difference in the allowance between Ian and Kathy
= 1.4 u - 1.35 u
= 0.05 u
= 0.05 x 1400
= $70
Answer(s): $70
