Question

Earl wants to earn enough money to purchase a bike that costs $515. For every lawn he mows he earns $25 and then gets a daily bonus of $15. What is the minimum number of lawns he would need to mow in 5 days to have enough money to buy the bike?

Answer 1

Earl will mow ≥ 18 lawns in five days

Explanation:

cost of bike / expected amount = $515

Daily bonus earned = $15

Bonus earned in 5 days = $15 * 5 = $75

Remaining amount would be = expected amount - bonus earned in 5 days

= $515 - $75 = $440

The amount remaining will be worked for in five days

1 lawn = $25

X lawns = $440

cross multiply

$25 x = $440 therefore x =
`(440)/(25)` = 17.6 lawns

In five days Earl will have to mow a minimum of 18 lawns to have a enough money to buy the bike

Answer 2

18 lawns

Explanation:

Expected sum = $515

Bonus for 1 day = $15

Bonus for 5 days = $15 × 5 = $75

Amount to be earned from mowing lawns in 5 days = $515 - $75 = $440

$25 ≡ 1 lawn

$440 ≡ 440 ÷ 25 = 17.6

The minimum number of lawns is 18.

(Note that we take the minimum integer greater than 17.6. If he mows 17 lawns, his earning from 17 lawns = $425 + $75 = $500)