X = 1 hr lessons and y = 1/2 hr lessons
x + y = 35......y = 35 - x
40x + 25y = 1115
40x + 25(35 - x) = 1115
40x + 875 - 25x = 1115
40x - 25x = 1115 - 875
15x = 240
x = 240/15
x = 16 <=== there are 16 one-hr lessons
and 19 half-hr lessons
Answer:
15
Step-by-step explanation:
Using the formular, Sn = n/2(2a + (n - 1)d)
where, n = 6: Sn = 6/2( -20 + 5(3)) = 3(15 - 20)
∴ Sn = 15
Answer:
° 3/2 × 4/15
Step-by-step explanation:
for checking a division problem use the product and one of the fractions to multiply. if the answer matches the other fraction then your division is correct.