The whole bill is $31.99 that is 100%. You can use mental math to determine exatcly 15% from $31.99:
1. 15%=10%+5%
2. To find 10% from $31.99 you should simply divide $31.99 by ten. Thus, 10% from $31.99 is $3.199.
3. 5% is half of 10%, then 5% from $31.99 is $3.199:2=$1.5995.
4. 15% from $31.99 is $3.199+$1.5995=$4.7985≈$4.80.
Answer: correct choice is B.
Answer:
2800
Step-by-step explanation:
Just round the 43 to 40 and the 68 to 70. So the problem then converts to 40x70 to get a rough estimate. 40x70=2800
About 11% of Americans wear contacts!
1. 28 x 3/4 = 21 kg
2. 1 hr = 60 mins
=》 1/4 hr = 60/4 = 15mins
Question: solve for r: 6 ^ (2r) = 800
Answer: 1.87
Step-by-step explanation:
6 ^ (2r) = 800
log(6 ^ (2r)) = log(800)
2r log(6) = log(800)
r = log(800) / (2 log(6))
r = 1.86537641979
round
r = 1.87
log can be any logarithm function.
6^(2×1.86) = 784.734328546
6^(2×1.87) = 813.365367336
