Wally counted 50 pennies from his piggy bank. He kept 80% of them. How many pennies did Wally keep?

Jamie went to home depot.she bought 25 bags of soil that cost $9 per bag.she bought 15 pots at $8 each, and she bought 23 bags of pebbles at $15 each.she used a coupon that gave her $5 off for every 100 dollars she spent. how much did jamie pay at the end?

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.