For 1 hour:
- Jennifer can clean 1/2 of her room;
- John cal clean 1/5 of her room.
Both can clean: 1/2 + 1/5 = 5/10 + 2/10 = 7/10
1 hour -------- 7/10
x hours---------- 1
x = 1 : 7/10 = 10/7 h = 1.42857 h ( or 1 h 25 min 43 s )
Answer:
8.3 * 10 ^5
Step-by-step explanation:
830000
To change this to scientific notation, we move the decimal 5 places to the left. The exponent will be positive 5 because we moved it to the left
8.3 * 10^ +5
8.3 * 10 ^5

Two lines are parallel when their slopes are the same.
12 total letters...5 vowels and 7 consonants.
probability of 1st letter being a vowel is 5/12
after replacing ...
probability of 2nd letter being a vowel is 5/12
probability of both occurring is (5/12 * 5/12) = 25/144 <===