What two digit number is three times the sum of its digits?

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

Find the exact value of each of the following. in each case, show your work and explain the steps you take to find the value. (a) sin 17π/6 (b) tan 13π/4 (c) sec 11π/3

Which statement is true about a number and its additive inverse? a. their product is always one. b. their sum is always one. c. they are always reciprocals of each other. d. their sum is always zero.