Third, according to the given formula, supplement the conditions of each question.

There are 80 monkeys in the park. How many orangutans are there in the park?

①80×( 1+ 3/ 10)

Supplementary conditions: there are three tenths more orangutans than monkeys.

②80÷( 1- 3/ 13)

Supplementary conditions: there are three tenths more monkeys than orangutans.

③80× 13/ 10

Supplementary conditions: monkeys are only 13 times as big as orangutans.

(4) 80- 13%

Orangutans are only 13 times as big as monkeys.