Can you help me with this square???

Arectangle has a width of 5 cm and a length of 10 cm. if the width is increased by 3, how does the perimeter change?

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)

An electrician cuts a 136 foot long piece of cable. one piece is 16 feet less than 3 times the length of the other piece. find the length of each piece