If angle ADC measures 23 degrees what does angle ABC measure?

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

Solve this riddle: i am an odd number. i an less than 100. the some of my digit is 12. i am a multiple of 15. what number am i?

Gabrielle's age is three times mikhail's age. the sum of their ages is 40 . what is mikhail's age? __ years old